"You've all arrived on a particularly exciting day!" the man guiding the NASA tour said over enthusiastically. "As of oh-nine-hundred hours this morning, the Cassini space probe has completed another death defying dive into the gap between Saturn's closest ring, and the planet itself! Cassini is nearing its end of life, so with little more to lose, we're trying the risky stuff. Who knows what could happen? Perhaps there's another undiscovered ring in that gap? Maybe even a small moon that has thus far escaped photography. But don't worry, we think the risks are relatively minimal, even now. But the rewards! We'll know more about the atmospheric conditions on Saturn than —"

"Mr. Cafferty!" Another man in a lab coat came running up to him.

"I'm with a tour, Hamilton. Can it wait?" Mr. Cafferty said, peeved by the interruption.

"No, sir. Sorry, sir. No one could find you earlier," the man said with a nervous look at the crowd of tourists.

"I left my phone somewhere," Cafferty said. He turned to the tour group. "We'll just be a moment. Please stay as a group. See if you can come up with any questions for me." He turned his back on them and whispered, "Yes? Out with it."

"The Spitzer team got some really exciting pings in the infrared, and they asked us to repoint our cameras."

"What? Now? During the dive?"

"Yes sir. It seems to be a comet swarm. No one's ever seen one before, and it just happens they were passing by Saturn."

"Well, you tell them they're out of luck. We're not hunting comets, we're making discoveries about the formation of large bodies in the outer solar system."

"Um, yes. It's just that we couldn't find you earlier, and they were very convincing…"

"You repointed the cameras, didn't you?"

"The swarm passed in a matter of hours, whereas we can perform another dive in a week. Saturn will still be there."

"Hamilton, I'm beginning to question why you are on this mission." Cafferty turned back to the crowd, and his broad smile was back in place. "Wow. What a lucky day indeed. I've just been informed that we have received a new imaging target. A once-in-a-lifetime cosmic event occurred just as the dive was beginning, and the team decided to realign our scientific instruments and capture that instead. Now, we're just outside mission control right now. The first images of this unprecedented event will be coming in in about…" he swung around to face Hamilton, who was still standing there, a bundle of nervous energy.

Hamilton jumped, realizing all eyes were on him. He looked at his watch. "Uh, eight minutes, twelve seconds. Sir."

Cafferty swung back toward the group, smiling excitedly. "Just about eight minutes." He paused dramatically, looking from face to face. "Now, I know I want to see those shots, hot off the press, and if you've come on a NASA tour, there's a good chance that you do too. What do you think, Mr. Hamilton? If we're really quiet and stay in the back, do you think we can go inside for a minute?"

"You mean like all the tours do, sir?" Hamilton asked quietly. Cafferty's smile remained firmly in place, but one eyelid began twitching rapidly.

Understanding dawned on Hamilton's face, and he said in a much louder voice, "Well, with such a good group as you've got today, I don't know how we can say no!"

"Excellent! Come on everyone! Hamilton, lead the way."

The group crossed the atrium, and Hamilton held open one of a pair of double doors. "Quietly now, this is where the magic happens," Cafferty said as the group went inside.

It was exactly what they'd expected inside, and the group started taking photographs. There were four rows of computer consoles, with several people monitoring them. Many were wearing headsets and speaking in tones too low to be heard by the tour group. The far wall was a series of huge screens. On the left was an image of Saturn with a blinking dot that represented Cassini's last calculated position. A dotted line showed the path of Cassini's recent dive. The middle screen showed a top down shot of Saturn with circles representing each of the rings and moons in their projected orbit. A yellow dot represented Cassini. The rightmost screen showed a model of Cassini with read-outs of all of its system functions.

"Everyone line up back here, along this railing," Cafferty said in hushed tones. "The photos will be coming through soon."

While the group was filing in, a group of scientists came to stand nearby, and Mr. Cafferty stepped away to conferred with them in angry whispers. "Bill, were you the one who made this decision?"

"Ryan, don't start. If you aren't going to answer your phone, someone is going to have to decide. They had a compelling argument, and the president himself endorsed it. Something that hasn't ever been seen before, versus something we'll get another chance at next week. I know you had some skin in this one, but I felt certain the science would win you over."

Cafferty sighed. "Alright then, tell me it was just the camera mount. Tell me the rest of the instruments are taking measurements on Saturn."

"No Ryan, it's the full suite. They wanted infrared and compositional information on these too. They also wanted radar, so we'd know when they'd reach Earth orbit. If they're heading toward us, it's a matter of emergency preparedness."

"But the polar aurora hasn't been measured this far north before! We may never get a chance to get those readings again either!"

"I'm sorry, but the decision's been made. We all think it's worth it."

Cafferty opened his mouth to argue some more, but someone sitting at one of the forward banks called out, "The first image is coming in now!"

"Thank you Rasheed," Cafferty said. He turned back to the tour group. "This is it. I'm sure you're going to want to get your cameras out. Do remember that there's a lot of work going on here too though, so please respect that this as a workspace." Then he turned back to watch the screen himself.

The middle screen had gone blank, and a line was moving across, from left to right at the very top. It got to the far right, then started again on a second row, and so on down the screen. It was still mostly black, but people gasped as the first bit of white to show up on screen. After another ten or fifteen seconds, the image was complete. Applause started at the front of the room and made its way back. Someone shouted out, "Woo!"

There were a hundred or so bright white balls in a roughly egg shaped distribution across the screen, each with a long tail extending back and to the left, fuzzing out around the edges. The image was quite clear, and the tails were detailed, but the comets themselves were indistinct because of how bright they were.

"I thought it would be in color!" a child's voice called out from the line of visitors.

Cafferty turned to see a father shushing a young boy. "The next one will be in color. We always take one, just for the public, but it takes eleven times more data storage and transmission, and ironically, contains less useful data. We have a program that combines all the layers, rather than feed it in raw, so once we have the image, it will come up all at once."

They looked back at the screen and had to wait what seemed like a very long time, then the image in front of them just popped in, in color.

The viewers started murmuring, and camera flashes went off. The ball at the head of the comet could now be seen as roughly spherical, slightly wider than tall. Overall they looked blue, with a distinct blue tail out the back, but there were speckles of other colors on the head of the comet, mainly reds and pinks and whites. Conversations could be made out among the scientists around the room, mainly discussing the swarm's regular distribution, and how similar all of them were in size. One of the scientists even approached the screen and held up an eight by eleven sheet of paper to one of the comets, then a few more. Each time, he just about covered the head entirely.

Then the next picture came in, black and white again. One of the computer techs moved the color picture onto the right hand screen for the public, while the black and white image filled the center screen, row by row. This image looked nearly identical to the previous image, except all the comets had moved roughly a foot to the right on the enormous screen.

Even Cafferty was getting excited now, and was huddling with the others in the group. "Carolyn, do we have any idea of the size of those comets, or of their distance from Cassini? The change in location between images looks… significant." The date stamp of each photograph was written on the lower right-hand corner. It was only three seconds between frames.

Carolyn began conferring with some of her colleagues. If they assumed the comets were composed of water ice, their albedo would tell them fairly accurately the distance to the swarm, they agreed, but the calculations would take longer than the time until the radar data came in.

They were so engrossed in their conversation, they didn't notice that another image had come in, replacing the previous one, until one of the visitors said, "Hey! That one's not in the swarm anymore."

They stopped all conversation, and looked up at the screen. The main body of the comet swarm was still an egg shape, evenly distributed across the right end of the screen, but now there was clearly one outlier.

"Rasheed," Cafferty called out. "Bring up the previous one."

After a few key clicks, the previous image came back in. It was clearly an egg shape, without any outliers. "And forward…" Cafferty said.

The image jumped about a foot to the right, with one bright spot out of place.

"There!" one of the techs yelled, pointing at the screen. There was an empty space just left of center, near the bottom of the swarm. Rasheed brought up the previous image, and the dot was there, then the next, and the dot was out of formation, to the left of the swarm.

The scientist at the front of the room slowly raised the piece of paper up to the misplaced dot. It was clearly larger than the paper. "That's not possible," someone said, but everyone was thinking it.

The next image was coming in, and row by row it was slowly replacing the current one. Not a sound could be heard in the room, save for the fans on individual computers, as everyone waited for what the new photograph would reveal.

The man in the front of the room didn't need to hold up his paper, the outlier was now clearly double the size of the others. "There's no tail on that one!" someone said.

"It's coming straight for Cassini!" Carolyn surmised.

A chilling silence filled the room, that was only broken by a click and a flash from the back.

"Cameras!" Cafferty yelled. "Security! Collect those cameras! No one leaves this room until all bags are searched!"

"Sadie, dear, do you have a moment?" Pandora's mother said as she stepped into the kitchen, sorting through mail. She sat down at their little breakfast table and placed several envelopes in front of her, and another group off to the side.

"Sure, mum," Pandora said. She stood at the sink, elbows deep in suds, with a long-handled scrubber in one hand, and a clutch of silverware in the other. She looked over her shoulder. "What'cha got?"

"I think it's time to discuss which A levels you'll be taking."

"Seriously, mum? Now?" She dropped the silver in the drying rack and shut the tap, then turned, wiping her hands on a dish towel. "I only just finished my GCSEs."

"Yes, dear, but you should have, over a year ago, shouldn't you? It's lucky the school board let you take them and all. And besides, you did so well, I thought you might want to broaden your subjects."

"Yeah, like what?"

"Well, like physics for one."

"Physics?"

"Well, you've a unique learning experience, haven't you? If that Doctor friend of yours can't teach you physics, who can, hey?"

Pandora turned back to the dishes. "And if I'm taking physics, I suppose I'm taking maths too?"

"And history…"

"History as well?" Pandora said incredulously.

"And why not? Who can say more about China's first emperor than someone who's met him?"

"And what job do I get with physics and history A levels?" Pandora called over her shoulder.

"Well, you've got your options open, haven't you?"

Pandora sighed. "It's not really like that, you know? Maybe you pick up a bit of history, but really it's about life, and what it means, and just… doing the best you can for people. Traveling with the Doctor… Life is exciting, and… meaningful. Yeah, that's the word. What I do everyday matters. But I these times too. The quiet times. Just chatting with you, and… doing dishes and stuff. I never appreciated chores before. I remember whinging on about taking out the trash and all, but now… It's just great, how absolutely normal this is, you know?"

Pandora turned to see her mother holding her hands up in frightened silence. There were a pair of soldiers in the kitchen wearing tactical vests and holding semi-automatic weapons at the ready. Standing in the doorway, was a dark-haired woman with glasses, wearing a lab coat over a paisley tie and a jumper covered in question marks. "Well, this just got awkward," said the woman.

Pandora had a moment of panic, thinking about her box all the way in her room.

"Stand down, men," said a short-haired blonde woman in a trench coat and grey scarf, as she stepped into the room. She thrust out her hand toward Pandora. "Kate Stewart, Chief Science Officer of UNIT. Sadie Sladen, we need your help."

"You… know me?" Pandora said, shaking Kate's hand with her own soapy one.

Kate didn't miss a beat, drying her hand off on a towel that hung from the oven handle. "Yes. We've been following you since you broke in to this country's most secure facility."

"Hiya. Remember me?" Osgood asked.

"You what?" Pandora's mother asked.

"Yeah, forgot to mention. Sorry, mum," Pandora said, then to Kate, "Are you arresting me?"

"Nothing of the sort. We need to get in contact with the President of the World."

"The world doesn't have a president…" Pandora said with narrowed eyes.

"She means the Doctor. We need to speak with him," Osgood said.

Pandora took a moment to think about what she should do. If she called the Doctor, would she be luring him into a trap? If she didn't, what would these soldiers do to her? To her mum? Was this one of those times when she should just stand up and take it anyway, for the greater good? Then came a sound that took the decision out of her hands. The echoing, grinding noise of the Tardis materializing.

"You lot are in trouble now, because here he comes!" she said defiantly.

"Sorry, that's my mobile," Osgood said, fumbling to turn her phone off.

"Miss Sladen, if you're under the impression that we're here to capture, or punish you or the Doctor, let me assure you that is not the case," Kate said. "I appreciate that you want to protect your companion, but we're here because we need his help. We are only hours from an alien incursion, and the Doctor may be our only hope."

Pandora looked back and forth between Kate and Osgood's earnest faces. "I'm going to need my phone."

The Tardis materialized in the corner of the already crowded kitchen of Madeline Sladen and daughter. The door opened up, and the Doctor leaned out, holding a diving helmet under one arm, and dripping water on the linoleum floor. "You pulled me out of a birthday party on Enceladus in the twenty-seventh century. I hope whatever it is, it's important." Then he noticed Kate. "Oh," he said. He tossed the helmet back into the Tardis, stepped outside and closed the door behind himself.

"Mr. President, Incursion Protocols are in place, and I'm here to brief you," Kate said. "Sam?" She held a hand out toward one of the soldiers, and he handed over a sealed manila folder.

The Doctor walked past her as he crossed the room. "Pandora, could you help me with this?" His eyes never left Kate's. Pandora helped with a couple buckles, and the Doctor shrugged out of the diver's suit. Then he turned to Pandora's mother and said cordially, "Ms. Sladen, so nice to finally meet you. Do you mind if I take a seat?" He pulled one of the chairs out from the breakfast table and sat down to remove the suit's boots.

"If I may continue, Mr. President," Kate said, breaking the seal on the folder.

"Don't call me that," the Doctor interrupted. "You may not have heard, so I don't really blame you, but I'm on vacation."

"And we've left you alone, even after you broke into the Black Archive. For which you still owe me a vortex manipulator."

"Ah, you'll have to take that up with my wife."

"Well, that's a write-off then. Yes, we got that you wanted to be left alone based on how you handled the theft of the Metabelis crystal. But the threat to the Earth is one that I'm afraid requires your attention." She read his face for a while, and finally added. "Doctor, please take a look at what I have, then decide what you want to do."

He made no move to dissuade her, so she continued. "Yesterday morning, Spitzer picked up what looked like a comet swarm heading for the inner solar system. Twenty hours ago, the Cassini Space Probe cameras were repurposed to get some images of this theoretical event." She opened up the folder, pulled out the top photo and laid it down on the table between the Doctor and Madeline.

"Too regular a distribution to be a natural event," he said immediately. She laid down a second photo showing one of the dots breaking formation, then a third where the swarm was all but obscured by the one object.

"Four minutes later, we lost contact with Cassini." She pulled out another photo. "This is a close up from that last photo. The rest of the swarm was just about side on, and this one was unobstructed." She laid it down on top of the others. It was highly pixilated, but it could be seen that the tail was actually an exhaust plume, and the shape of the main body hinted at something robotic. "Does the design look at all familiar?"

The Doctor picked up the photo and looked at it closely. "Do you have any idea as to the size of this object?"

"Yes," Kate flipped a few sheets. "Approximately .25 meters around and one meter long. Doctor, if you've seen these before, who are we up against?"

The Doctor stared at the photo for a while longer, then set it down. "No idea. I've never seen them before."

Kate went on. "Eight hours later, we lost contact with Juno. Half an hour ago, it was the Mars rovers and orbiters. All of them. We've since gotten confirmation that we haven't heard from either Voyager probe, the Pioneers or New Horizons in more than a day. Spitzer has taken a few more shots of the swarm, and found that it has broken up. One is heading for each of the observers and explorers in the solar system. Akatsuki, Stereo, Hayabusa 2, Dawn, Osiris-Rex, but the vast majority are headed straight for Earth. At current estimated speed, they will be here in under four hours. And they are destroying everything the come into contact with."

The Doctor pulled a magnifying glass from one of his pants pockets and examined the robotic closeup again. "How many are coming for Earth directly?" he asked without looking up.

"Eighty-three," Osgood said. "We don't have the resources to track them individually, but that's the main cluster, and it's heading this way."

"And, what year is this? 2017? You've got roughly ten observatories on and around the moon, but hundreds of satellites in orbit. Let's assume they give most of those a miss and concentrate on the significant ones. You need to evacuate the ISS and the UNIT Space Platform, now. And we'll need to be there when one of these lands."

"Doctor, we can't let them land. They destroy everything they touch."

"I don't think their aim is destruction. I think they are simply homing in on radio transmissions. When they reach the source at six hundred kilometers per second, destruction is just something that happens."

"How are we going to predict where they land?"

"There are literally millions of radio transmitters across the world, and the swarm can pick probably sixty at most. We can improve our chances a bit by organizing a shutdown of radio and television stations in the ten minutes or so before they hit. Now there are a number of extremely probable targets, Jodrell Bank and the Woodpecker come to mind, but only one that I can think of that they couldn't avoid."

"Arecibo," Osgood said.

The Doctor stood up. "Bring me my big-old poncey plane, and break out your tildes! We're going to Puerto Rico!"

The plane had been fueled up and ready at the closest airport before UNIT arrived at the Sladen flat. The soldiers were mainly there to get the Tardis into a lorry and to the plane. Pandora swiveled around in a deeply cushioned chair with her box on her lap, drinking sparkling fruity water, and watching the spectacle of a tightly run world organization at work.

There were twenty other people at Kate's level in there, and each of them was on the phone for most of the ride. They were organizing a world-wide shutdown of television and radio broadcasts, coming up with a believable cover story about a 'period of silence to honor all the media personnel killed or imprisoned in wars and oppressive regimes'. Several UNIT heads from various countries wanted to shutdown their radio telescopes as well, but the Doctor vetoed it. The swarm needed viable targets, or else it would go after HAM operators and the like. Even still, most of the weather, communications and spy satellites were uploaded with instructions to go radio silent for the target period. The rest of the trip, they were organizing quick response teams to be sure that UNIT personnel were first on the scene of each of the landings, wherever they might be. Pandora knew there must be twelve languages being spoken around the massive table, but she understood them all as if she'd been born to them.

The Doctor, Osgood and a UNIT captain named Josh Carter were putting together a plan to catch the object, now being referred to as a 'locust', as it came from a swarm and looked nothing like a bee. There was some concern about what it would do to the radio telescope at Arecibo, but mostly, the Doctor felt sure he could identify its origin and purpose if he could get one intact. He mentioned an energy web, and Osgood was talking about an inertial brake. It all got a bit too timey-wimey for Pandora, and she pulled out her tablet. She was curious as to how the citizen scientists of the world would react. The ones that UNIT couldn't silence or ignore. But so far, her favorite blogs were silent and apparently oblivious.

They touched down on a dirt airstrip that looked way too small for a plane of this size to land on. It must have taken advantage of some of the alien technology that UNIT was privy to though, because it landed smoothly, and with room to spare. They had less than twenty minutes to reach the telescope by waiting jeeps, but they had a plan.

She rode in the back of a jeep with Sam, the soldier from her apartment this morning, as well as a couple more she hadn't met. She was a little put out, not getting to ride with the Doctor, but he was still heavy in conversation with Josh and Osgood, and with the equipment they were bringing with them, there was no room. She didn't make a fuss, but she felt like a serious third wheel, along for the ride.

Sam must have seen the look on her face though, because he smiled and said, "Not much for all the science chatter, eh?"

"Actually, I was always quite good at science. I love astronomy and chemistry and that, but the Doctor's on a whole other plane. I'm surprised anyone can talk to him when he's on about it. What's Osgood's deal?"

"Just about the best the Earth has to offer, and with the clearance to learn from all the goodies from out there," he said, pointing up. "I don't pretend to understand it. I just nod along when she's on a tear, and between you and me, Carter's out of his league too. He's good, but on a human scale. But she can get all this stuff working, she figures it out. You know, she may be a Zygon."

"What's a Zygon?"

Sam laughed. "You don't know about the Zygons? Ask your Doctor about it sometime. But the point is, I don't even know if I've ever met the human Osgood. It's possible she's only this smart because she grew up out there. Not that I'm prejudice or anything. I'd take a bullet for her either way. Have done, a time or two. Just… you've got to wonder."

They lapsed into silence along the bumpy and muddy ride up the side of the mountain. Once they got through the entrance gates, the road was paved, and shortly after, they came over the lip of the crater and could see the telescope proper. Pandora stood up, holding onto the roll-bar to look across at the massive white dish surrounded by three tall towers. "It's enormous!" she said. "They paved the inside of a volcano!"

The soldier in front of her turned in his seat. "It's not, actually. It's a sinkhole, not a volcano. They call it a karst."

Pandora didn't care what they called it, it didn't change how big it was. She'd seen it in movies, like that Bond film with Pierce Brosnan, but figured it was movie magic that made it look so big. If anything it looked bigger up close.

The two jeeps pulled to a stop, and everyone piled out. They only had five minutes left. The Doctor started tinkering with the equipment, and Osgood started giving orders. Pandora decided to just wander over to the edge and take in the view.

Osgood was at her side, surprising her. "Hey. We need you to set up the inertial brake."

Pandora smiled sadly. "I appreciate it, but you don't have to give me a job just to make me feel useful."

Osgood looked back puzzled. "We didn't just waste taxpayer money bringing non-essential personnel just for the weight. You're here because we need you. This device here," she said, lifting up a gun-metal briefcase-sized item, "needs to get up there." She pointed toward a triangular platform suspended high over the center of the dish. "Then you need to activate it. This button here. Okay?"

"You're not going to do that?"

She smiled. "No, I don't think so. I can't handle heights. I'll be on the computers over here. These men are securing the base, and evacuating civilians in case we fail. The Doctor, Sam and Josh are going to place the three endpoints of the energy web. We only have three minutes left until the window opens. Sam's heading up in the lift now. You can make it if you run. Go!"

Pandora took the device by the handle and ran. Sam held the lift to the closest tower. When they got to the top, she had to run across what basically amounted to a rope bridge, with her box in one hand, and the brake in the other. She was higher up than she'd ever been, and one misstep would send her plummeting to the concrete reflecting dish some thirty stories below.

She heard a loud base pulse off to one side while she was half way across the bridge, and she took a tumble when she instinctively looked for the source. She threw her arms up and over the wires that acted as rails, and managed to get both feet up on the grate of the bridge. She saw that the Doctor had activated his device. A second pulse came from behind, and she knew that Sam had activated his as well.

Miraculously, she'd managed to maintain her hold on both her box and the brake, and she started running again, making a mental note not to let it distract her when the third endpoint started up.

She got to the center, and there was a bridge in a ring shape that went around the triangle in the middle. This is where she was supposed to deploy the brake. She set it down on the grating, and pressed the button. The top folded back, and a second layer folded up on the other side. It reminded her of wind blocks on a camp stove. A ring of energy, about the size of a compact disk, floated about half way up in the middle of the device.

Okay. It was activated. Pandora wasn't sure she wanted to be here when the locust came crashing down. She started running back the way she'd come, while Sam was running toward her. The third bass pulse hit her then, and a wave of energy crackled along the space in between the three endpoints. For a moment, she could see the weave of the net just overhead, then it vanished. She stopped, a third of the way along the bridge and looked up into the sky.

There was a sonic boom, and the locust was visible. It was a black spot, surrounded by a fireball, and streaming a long oily tail. She thought back to the meteor Abaddon, and how slowly it seemed to move from tiny speck to blotting out the sky. This was a completely different experience because the locust wasn't visible until it was well within the atmosphere, and it took only seconds to fall to Earth. Suddenly the net activated, a bright blue web flashing just out of reach. It sounded like an explosion, and then it was over.

The locust was suspended, face down, in the air above the inertial brake.

The Doctor came running along another bridge from the next tower, taking his hoodie off as he came. He rushed up to the locust and dropped to his knees, pressed the button on the inertial brake, and caught the locust inside his hoodie as it fell. He looked up at Pandora, Sam and Josh. "It's cool to the touch." Pandora reached out to touch it, but the Doctor pulled away. "Still best not to. No bare skin in case of electrical discharge or something. It appears dormant, but we'll know for sure once I get this into the Tardis for analysis."

"Sorry sir, my instructions are to ensure that gets to the Black Archive for examination," Captain Carter said.

"But I have far more sophisticated analytical tools in my Tardis…"

"I'm sorry sir, but my orders were very specific."

"In that case, I'd like a word with your superior! Oh, wait, that's me!"

"Actually, in military matters, Doctor, that's me," Kate Stewart said, arriving on scene. She walked toward them along the swaying bridge holding out a large plastic chest lined in foam rubber. "And given the destruction these things are causing all over the world right now, this is clearly an item of military significance."

Josh took the Doctor's hoodie, and its cargo from the Doctor, and placed the locust into the locust-shaped hole in the foam rubber. Kate snapped the lid shut while Josh handed the Doctor back his hoodie.

The Doctor fumed all the way back to the airport, then all the way back to London, then again all the way to the Tower of London. "What's the point of putting me in a position of giving orders if you've no intention of carrying them out?"

He sat in the back of the lab, biting his thumbnails and pacing, while UNIT scientists worked on the locust under a spotlight. It was a mechanical object, ovoid, like an egg that had been stretched out. Its shell was a carbon grey with red markings, and it had a lens at the front, and a thruster array at the back. Parts of it were segmented, suggesting that they opened up, or were meant to be removed, but there were no signs of screws or other fasteners. So far, the scientists had bolted it down to a stainless steel workbench, in case the thrusters fired, and covered the lens with an opaque cap. "No sense in telling them all about us while we're trying to learn about them," Osgood noted.

The scientists were dressed in clean suits, complete with goggles and ultra-fine particle masks. They worked with fine tools, trying to pry it apart at any of the segments, but the seams were just too narrow. Any tools they could manage to wedge between the seams only bent, without so much as wiggling the segments.

Next, they used a portable X-ray to peer beneath the surface of the locust. That proved no more effective, because the X-ray, and later the ultrasound registered it as a solid black mass. "Well, it would, wouldn't it?" the Doctor spat. "That's coated in danedium for re-entry. Only a millimeter thick, but eight times as dense as lead. If you'd let me use my Tardis, I could —"

"Thank you, Doctor, that won't be necessary," Kate said dismissively. "We have rather more invasive means at our disposal."

The scientists next brought in a laser cutter. "Based on Zygon designs," Osgood said. "One of the advantages of securing refugees."

The Doctor looked over at his Tardis, and resumed pacing.

The laser itself was just a pen sized device, but it was attached to the large, wheeled energy source by a boom arm pivoted in three places. Pandora, the Doctor and the others were all given ruby-tinted safety glasses to wear, then the laser was activated. The Doctor scoffed at his, and hung one temple over the neck of his t-shirt. The laser glowed a blinding green, and the scientist working with it moved it painstakingly over the surface of the locust. First she focused on the red, segmented section along the side, then on the grey section just behind the lens. A minute or so later, the laser was shut off. "No go," the scientist said. "We haven't even blemished the paint job."

"Oh, this is ridiculous," the Doctor said. He strode purposefully toward the locust, digging into his inside hoodie pocket.

The scientific team scattered, pushing the laser out of harms way. "Doctor," Kate called out in a commanding voice.

He ignored her and stopped in front of the workbench holding the locust down. He pulled out his sonic screwdriver and activated it, the tip glowing red.

The locust whirred to life, segments extended, twisted and flexed. The forward and rear ends of it separated and folded upward, then the sides moved outward and reconnected. The bolts and metal band securing the locust to the table bent and tore with a terrible scream. A blade extended from the center of the now open locust, pointing upward, and the entire device began to glow and hum.

The Doctor slowly approached the device, looking inside the reconfigured dish-like shape of the locust. He turned to look fearfully at Osgood. "The Black Archive is secured against outside communication?" he asked.

"Yes, of course," she said, a hint of worry in her voice.

"Even sub-space?"

"Yes, why?" she asked.

"On all twenty-two bands?" he pressed.

"Doctor, there are only eleven sub-space bands."

"And each one has a supersymmetric pair!"

"Doctor, what's going on?" Kate Stewart interjected.

"Well, the good news is, we now know the purpose of the locust."

"What, Doctor? What are they here for?"

"To seek out and announce the presence of any sonic technology."