They arrived at the place where the lights of the monoliths intersect. It pointed to the middle of the lake but when they arrived at the shore, there was nothing there. The alien water looked still and silent so they stood there at the beach, puzzled. Then suddenly, the water rose then broke and a structure rose out of the surface. Metallic liquid poured away from it, revealing something that looked like a shed. Its roof and the ceiling under it were shaped in octagons and built from the same dark material as the monoliths and the walls were open on every side.

Then cobblestones shaped like octagons rose out of the water and formed a bridge from the edge of the lake and to the island structure. They took that as a sign for them to pass so they crossed the bridge. When they arrived at the island, they saw at the center of the floor, a passage leading onto a door shaped like a trapezoid, narrowing at the top.

Scott signaled for Cora to stay behind and watch their exit. Cora glanced at K but she nodded and took cover among the pillars while they went down the passage and approached the door. Scott went forward to examine it and saw no locks or handles.

There might be some hidden mechanism to open it, he thought. He ran his hands on the surface, searching for a catch, when SAM said, "I detect forced signs of entry."

His hands went still. "Forced signs of entry?"

"Yes. There are paint marks on the walls and burns caused by mass accelerated weapons," SAM said, looking through his eyes and at the door, analyzing the minute scratch marks and scorch residue.

He looked back to his companions. "So…we're not the first ones here?"

"That's interesting," K said. "This means whoever they are have gone past the monoliths which, we know for one, cannot be activated without help from an AI."

"But they haven't fixed the planet," Marcus pointed out.

"So they must still be in there," Scott finished.

"Maybe," K said. She walked over to the door and looked up at it. "This is getting fun," she murmured. "Now how to open the door…"

"Scott, if you could move closer to the door I can try to override the lock," SAM said.

"You're a genius, SAM," K said as Scott held his omni-tool before the door so SAM could work on it. "How are you unlocking it?"

"This door is using the same encryption as the monoliths. Using the glyphs from the monoliths, I am currently testing combinations that will unlock the door."

"So you're guessing?" Marcus asked.

"In a manner of speaking."

Scott's omni-tool glowed and the door opened.

"Great job, SAM," Scott remarked, as they gazed into the dark maw of the vault.

"I did nothing. I have not yet finished entering my solution when I was interrupted."

They looked at each other. "Interrupted?"

"That's weird," K remarked, frowning. "So why did it open then?"

"Unknown."

Scott turned his attention back to the vault, gazing into its darkness. Then he shrugged and said, "Well, the door's open so let's go." He nodded at Marcus and took point for them.

The door opened into a passage leading down into a cool underground. The chamber was dark and illuminated with the green light of its etchings like the monoliths above. They flipped on their lights and saw they were in a vast octagonal chamber with a triangular depression at the center of the floor. But it was empty.

"Hmm, that's surprising," K remarked, walking around the room with her scanner. "After all those trekking, I didn't expect this would be so empty."

Scott looked around the empty room, whirling for the one thing they need the most and found none. "That can't be right. The one at Habitat 7 had a console we needed to work on," he said, his heart sinking. If this vault couldn't help them, then they're doomed.

"Really? Hmm," K wondered. She stepped closer to the wall, staring at the glowing etchings. "Maybe not all the vaults have the same layout," she suggested. "There must be some secret here. Maybe a secret entrance." She moved closer to the walls and poked at them, running her fingers on the lines. Scott watched her, then decided to follow her lead, crossing the steps forming a triangle in middle of the room to search the wall.

Something rumbled. Heavy, like the shifting of a stone wall. They stood still, staring at each other, when another rumble occurred. Scott felt the floor moving then he realized the rumbling was coming below him. He jumped back and scrambled to the top of the steps. He saw the triangle he was standing before slid open, revealing a gap in the center of the room leading down.

K looked open mouthed at the opening then at him. "You're a genius!" she exclaimed.

"I..didn't do anything," Scott said, looking at the opening.

"You know, there's a lot of things opening with someone saying they didn't do nothing that I'm starting to think that it's not coincidence anymore," Marcus observed. "Like, it's making it easier for us because some horrible monster is at the end of it."

"You think this is a set-up?" Scott asked.

Marcus gestured all around them. "We're in space in some alien vault. It wouldn't surprise me if we ran into some sacrificial chamber down here."

Scott chuckled and shook his head. "You've been watching too many movies."

"Says the space marine. And people ask why they always die first," Marcus answered then mock sighed. He walked over to the edge and peered down below. "How far down d'ya think it goes?" Scott joined him and stood gingerly at the edge. He took out a half-spent thermal clip and dropped it in the hole. But instead of falling, it was suspended in the air. Then a blue shimmer encased it and only then did it descend below. Slowly.

"That can't be air pressure. Electrostatic?" K said, craning her neck down the shaft as safely as she could. "Ah! Gravitation. Maybe there's a gravity well at the bottom."

They watched the clip slowly descend into the shaft. Finally, it stopped, glowing faintly in the dark.

"Huh. Either there's a ground down there or it's just floating," Marcus suggested.

"Definitely not floating," K said, peering down the shaft. "The light's not moving. I think there's a floor." She looked at them. "Well? Should we go?"

Marcus shifted his legs as he squatted. "We know there's a way safely down there. But how can we go back up?"

"Maybe the same way we came down?" K answered. "Anyway, I can make a singularity at the bottom and we'll fly out to here with your jetpacks. So, can we go now?"

The two looked at each other. "Hey, I can take point but if I see eggs down there, I'm noping out of here," Marcus said. He gave a signal and he and Scott dropped one after the other. It was a long drop but they arrived intact. They arrived at a chamber just like the one above them. They went into defensive stance as soon as they landed and waited, sweeping the area. The place was silent and still; there were no hostiles waiting for them so they called K down to join them.

The chamber led to a long passage then into an enormous cavern. There were no walkways so they have to walk and jump on the blocks built into the cliffs. Sometimes, they have to use their jet pack to jump on top of the pillars made of octagons. Ferrofluid ran on gutters, illuminating the walls with blue light and there were octagon shapes standing here and there blocking their way. They were glad of that because remnant bots started appearing and attacked them. Some even appeared instantaneously in midair, ready to grab them out of cover and into the lasers of their fellow bots.

"Lots of Sexylegs," K remarked at the bodies of the hopping Remnant bots they just defeated.

"Please don't call it that," Marcus said, glancing away from the bots. Their limbs do look like legs, only with thick thighs and slender calves.

Scott smirked at him. "What's wrong, Zola? Afraid you'll shoot the wrong gun?" Then he and K started laughing while Marcus vowed that he'd get back at them later. Scott fiddled with as much consoles as he can. Some of them just make the same octagon shapes appear and disappear. Some made the octagon pillars rise from between chasms for them to jump to as bridges or steps to a ledge. There were also strangle little circles adorning the walls with wiring running from it, making the walls look like a giant circuit board. SAM said it detected a touch interface. They tried with their hands but it did not react so they left it alone.

"There is alien organic material on the surface of the console," SAM said as Scott worked on the latest one. "It is a fresh sample. Therefore, they may have been here recently."

"Maybe they're our intruders," Scott remarked. "Is it the same DNA with the aliens we encountered at Habitat 7?"

"No. It is different."

Marcus whistled low from his post, watching for anything that'll try to creep up at them. "So, we've got another alien."

"I certainly hope they're friendly this time," Scott remarked. "Maybe they own this place?"

"Hmm," K said, running her own scanner over everything and anything she can reach. "Maybe but I'm sure they didn't live here. I've seen a lot of tech and I tell you, these aren't meant for habitation or anything for organics. Also, I see traces of mineral build-ups here, in a pattern consistent with high pressure and high velocity. Like made by gases passing though a vent."

"That is possible," SAM said.

Scott stopped fiddling with the console to gape at her. "A vent? A vent for what?"

K shrugged. "No idea. But maybe we'll know if we follow it in."

Scott went still as he thought more on this. "If it's not meant for organics, then why is there a door with a lock?"

"A question for the ages," K replied and grinned at him. "Here's the adventure you're looking for."

They stopped for a moment, letting K take scans of the strange wall. He would've run thought it, appreciating it only by its use towards accomplishing their objective, but he let K indulge her curiosity. Because as she chattered to herself while scanning, he was reminded of Sara, who does the same thing when she's around very old structures. Raving about some dead civilization even at dinner time. Sara would have studied every inch of this structure like K was doing now. He doesn't get the fascination of the past, he does understand how it is to care deeply about something.

Sara should have been here.

But she wasn't and so they must do what they could at the present. And at the present, he's not the only one who cannot appreciate the strange wall, because Marcus was mouthing something, tapping impatiently at his omni-tool showing a big round clock.

"Alright, K. Time's up. We really need to get going," Scott said and herded her out of the room. They proceeded to the lower bowels of the structure. Some corridors lead to room where the robots were being assembled. Some were just an unending stretch of walls, with the strange holes in them. Some passages were barred and they had to solve sequences to open the doors so they could proceed. As they passed through, Scott felt as if they had entered into a large factory. What the factory was it for, they don't know. That did not reduce the feeling that they're walking in a trap.

He led them deeper into the vault when he chanced to glance at the corner and saw some foot prints. It was hard to tell which race it belonged to as it was badly smudged. Then he saw something glowing just beside it.

He walked towards it and picked it up. Then he waved at the others. "Hey, take a look at this."

Marcus and K came back and they all stared at the thermal clip he was holding aloft. "So…the intruders are maybe one of us," Marcus said.

"Maybe it's the missing Pathfinders?" Scott suggested.

K studied it for a bit longer. "Maybe. I don't know," she said finally. "If they are, they must be crazy smart. You need SAM to activate the vault and as far as I know, none of them were equipped with one since the Nexus AI was badly damaged."

"The aliens?" Marcus suggested.

K waved the glowing object at him. "Those aliens use our thermal clips?"

Scott turned from her and looked once more at the footprints. "Huh. Let's puzzle over it later." He pocketed the thermal clip and huffed his rifle higher as they went inward. "This vault just keeps on giving, doesn't it?" he asked as they jogged.

They arrived at a central chamber. "I think this is the end of it," K said, looking around the room. It was illuminated by a large energy beam at the center of the room running up into a sort of chimney with walls made of stacked plates that kept undulating. Both four sides of the chamber had tunnels opening out and up, much like the tunnel they arrived in.

They walked around the chamber until they were sure that it was empty besides them. "So. No big bad monster here," Scott said to Marcus.

"Yes. But where's the people who went in before us?" he asked and stepped near the ledge to check at the chasm below.

"Maybe they got out before we came in," K said.

"Wherever they are, they're not our responsibility," Scott said, with a nod at the console just beside the center of the room. Scott went near and examined it.

"This one contain more functions than the consoles we passed by," SAM said.

"So..kind of the master control. Can this one fix the atmosphere?" he asked SAM.

"Unknown. Move your omni-tool closer so I can perform a test."

He let his hand hover above it and SAM started working.

"I have found a command for climate manipulation," SAM said after a while. "Should I run it?"

Scott looked at the other two who nodded. "Do it."

"Initiating. Please stand by."

They listened to the console whirring as it worked when he felt his body freeze. "SAM?" he asked in panic.

"We are being scanned. Standby."

"Scott? What's happening?" Marcus asked, his gun clacking as he drew it, looking worriedly at Scott who was standing too stiffly before the alien console.

"I don't know!" He tried to struggle but no matter what he did, his body won't move. It seems like he was under paralysis except he can breathe and speak.

They heard a loud, low mechanical sound. The paralysis disappeared and Scott landed in a heap. Marcus immediately grabbed him and dragged him away from the console.

"What the fuck was that?" Marcus asked as he helped Scott to his feet. They stared at the console which suddenly projected a hologram of a...planet.

"It is sending us a nav point. Uploading now," SAM intoned. "The navpoint indicates a planet on a system at the other side of the cluster."

"A planet?" Scott asked, frowning. Then an idea occurred to him. "Perhaps with a vault like this too?"

"That is possible. However, it does not tell anything more than the navpoint. A further study of this vault might reveal-"

The reason for SAM's interruption was the sudden increase in intensity of the center beam's light. It also has changed color.

"Pathfinder. I'm detecting a large energy build-up below you. It's coming closer," SAM said, as the light changed from white to angry dark purple and blue.

"What does that mean?"

"Run."

They started running back to the place they entered from. Scott happened to look back and saw a dark, sparking energy cloud emerge from the floors and filling the chamber. "I don't like the look of that!"

"Keep going! It's catching up!" Marcus yelled.

They jumped over the pillars, jumped over chasms, scrambled over ledges and ran without looking back. Some bots appeared before them but they only shot suppression fire at it, ducking at their shots and kept running. Finally, they arrived at the upper level just before the one leading up to the main door and found it locked. "Shit! We're trapped!" Marcus shouted and started bashing it.

"Scott! There's a console nearby. Maybe you can override it?" K suggested.

Scott looked at it and found it a little far from them, while the energy cloud was seeping in fast. There were no other options so he ran and hovered, no, almost pushed his hand down on it.

"C'mon, C'mon, c'mon", he rattled off, looking at the energy cloud closing in on him.

It was too late. He ducked down as the cloud enveloped him, his shields dropping fast and warnings sounded inside his helmet.

"Scott!" He heard K yell. She created a biotic shield around her and Marcus just before the cloud enveloped them. It sizzled as it hit the barrier. But soon, K looked strained, as the cloud ate away her barrier while Marcus continued bashing at the door without success.

"Chamber sealing," SAM intoned.

Suddenly, the energy cloud started being suck back in. Scott held on at the console, but Marcus and K had not expected that and so got knocked off their feet. They started rolling back into the chamber, screaming. Scott held out a hand as Marcus passed by.

Marcus caught it and held out his hand for K. She passed by him, reached…then missed.

"K!" Scott yelled.

Marcus stretched out his leg. K managed to grab onto his boot, and they held on as all the energy cloud was sucked back in until the doors closed with a clang. They fell to the floor and lay there on the floor panting and gasping.

Then Marcus started laughing. He rolled over and put his hand over his face. Scott broke into a grin then K also started laughing.

"You alright?" Scott asked them.

"I'm fine. We're fine," Marcus said and stood up, shaking himself. "No face-hugging monsters here, but that was a close one."

Their comms cackled and they heard Cora's voice. "Scott? Marcus? K? Are you there?"

Scott pressed on his omnitool to answer her. "Yeah. We're alive. We've activated the vault."

"I thought so. The air was clearing up as soon as the monoliths started emitting light. Are you alright? Storm's coming so we better move out fast."

"Copy. We're fine. We're coming out in a few minutes."

"I'll inform the Nexus that the mission is a success." There was a pause. "Good job, Scott."

Scott paused, remembering the time he overheard them talking about him being the Pathfinder. "Thanks," he said, out of politeness. He didn't need anymore drama in his life. He's got more important things to worry about. "We'll meet you at the exit. Ryder out."

They trudged out the vault and emerged onto the island. Cora emerged from the pillars to meet them, relieved and glad that they made out of there alive. As she talked, Scott looked beyond her and saw that the monoliths have transformed into towers emitting a beam of light into the sky. Around each beam, a powerful storm swirled around it.

His omni-tool beeped. The air was already cold.