The Planet Express crew all arrived at their headquarters at about the same time, with Amy, Fry, Leela, Bender and Dr. Zoidberg all having hoofed it, and the Professor and Hermes pulling up in a taxi that had been delayed by midday traffic. They all looked up to see the building sheened in a translucent purple light, and the Professor immediately knew what had transpired.

"Damn it!" he cried, shaking his wrinkled fists. "That little green bastard Zim has put a forcefield up around the entire building!"

"Great! How are we supposed to get in now?" moaned Fry, rubbing his neck and still smarting from his museum duel with the Irken pest.

"Search me," replied the Professor - not that anybody wanted to - as he shrugged his shoulders.

"Well, guess we'll just have to wait this one out," said Bender, and he ignited another cigar with the lighter mounted in one of his fingers.

"No way!" snapped Leela as she spun to face Bender. "Who knows what that little creep and his robot are up to in there? For all we know they could be building a doomsday device!"

Everyone gasped and drew back from the building, while within, Zim laughed out loud as he admired his handiwork.

"I don't know how I do it, Gir!" he chortled. "Sometimes I even amaze myself!"

By now he was wiring a final series of connections into the Voot Runner, which had nearly finished its self-diagnostic and repair cycle and looked much the same as it always did - except for the giant engine and exhaust mounted below it, borrowed from the Planet Express ship. That vessel sat in its usual place on the launch pad ahead, looking none the worse for wear except for the damage still visible along its nose from Zim's hell-bent flight the other day, plus its newly-missing propulsion system.

Gir was busy standing on his head, humming to himself, and thus took no notice of Zim's self-aggrandizing, until his master reached out and grabbed Gir by one of his small, seemingly-unconnected legs and dangled him slightly off the ground.

"There it is, Gir!" beamed Zim proudly. "Our ticket home! Say good-bye to the filthy 30th Century!"

"Bye, century!" chimed Gir, waving his hand at no one. Zim then dumped Gir to the floor, leaving the little bot lying there in a small heap before Gir regained his feet and began to march after Zim. The Irken invader walked over to the Voot Runner and opened the canopy, then reached inside to flick a series of switches and begin warming up the engines, old and new alike.

"Soon we will leave this place far behind and return to our mission!" vowed Zim, wondering how much he had been set back by losing a week's time - assuming that he and Gir could even get back to the exact point from which they had departed the 21st Century.

No matter, thought Zim. A few days early, a few days late, blah blah blah, big deal! The key was getting back to Earth and preparing that horrible blue globe for the eventual coming of the Irken Armada. The Tallest would undoubtedly be pleased when he accomplished that, regardless of what their future selves had said. Forgotten about Zim, indeed! They would not forget him when his mission was completed, oh no, they would not.
Outside, the Planet Express staff still searched for a way to get back inside their building, but the force field surrounding the structure seemed to extend everywhere.

"Professor, don't you have some kind of remote override?" queried Leela.

"Do I have a what?" replied the Professor, hard of hearing again.

"Isn't there any way to shut down the force field from the outside?" Leela asked again, a tad more exasperated this time.

"I'm afraid not, Leela," responded the Professor more coherently. "All the controls are located inside my lab."

"Can't we just blast through?" offered Fry hopefully.

"I'm afraid not, Fry," said his wrinkled nephew. "This baby was built tough, and the only way you might possibly penetrate it would be to short it out."

"With what?" asked Amy, trying to sound important in her intern's role, even though her rich-as-anything parents could easily buy the company a hundred times over.

"Well, something along the lines of Dolomite would probably work," responded the Professor. "It has mineral properties that could possibly shut down the field if applied in sufficient quantity. The question now is where can we possibly get some?"

Bender looked up nervously at the mention of Dolomite, knowing full well it comprised almost 40 percent of his structure. He hoped no one else remembered that as he slowly began to shuffle away, trying not to draw attention to himself.

"Hey, I think Bender's got some Dolomite in him!" shouted Fry, pointing to his robotic friend, who was trying to make good his escape.

"Shut up, Fry!" growled Bender under his alcohol-laced breath as he continued shuffling away, a tad faster now.

"By gosh, you're right, Fry!" exclaimed the Professor. "Come over here, Bender!"

"No way!" shouted Bender as his co-workers began to close ranks on him. "I'm not getting my systems scrambled for you guys!"

Bender opened his chest housing and produced an empty beer bottle, which he quickly shattered against his side. He then held it menacingly in front of him, trying to ward the others off as he moved away from the building and continued to back up. He was so engrossed in watching who was in front of him that he didn't see Leela down on her elbows and knees behind him, and without warning he toppled right over her and fell to the ground on his back. It was a trick the crew had used before, knowing that Bender was almost helpless in that position, like a turtle lying on its shell.

"Aw, not again!" moaned Bender as the rest of his so-called friends surrounded him.

"Everybody grab an arm or a leg!" shouted Leela to the rest of the staff. They all reached down and took hold of Bender's limbs, and then with a supreme unified effort managed to lift him off the ground.

"All right, people, start swinging him back and forth, and on three, toss him at the force field!" commanded Leela.

The group then started swaying, slowly at first under Bender's great weight, then faster and faster as they picked up momentum.

"No, no, no!" protested Bender, who was beginning to get a little bit dizzy from the constant back-and-forth motion.

"One ... two ... three!" ordered Leela, and then all together the Planet Express crowd hurled Bender headlong at their fortified headquarters.

"Ahhh ..." Bender began to yell, only to have his flight end just a second later when he hit the forcefield and got stuck to it, sparks of energy distortion flying everywhere.

"Ow! Ow! Ow!" he moaned. "Turn it off! Turn it offff!"

The forcefield began to shimmer and buckle, almost as if stiffening, like a living thing. It surged twice with a bright white light, causing Bender to spark even more furiously, until finally the entire field shut down from top to bottom, like a sheet being pulled from a bed, and ultimately and mercifully deposited a battered Bender on the sidewalk.

"Oh man, what a hangover!" he managed to blurt out as he lay there steaming and staring up at the sky. The rest of the crew didn't stop to tend to their fallen friend - he was too much of a jerk too much of the time - but instead rushed into their headquarters in hopes of stopping Zim. They arrived in the landing bay to see their ship's engine mounted underneath the much smaller Voot Runner, and Zim and Gir already inside the cockpit of the smaller ship and preparing to lower its canopy.

Zim, who was attired in his purple Irken battle armor, heard and saw his futuristic antagonists as they entered, and sneered at them.

"Fools!" he shouted. "You are too late to stop Zim!"

He pressed a button on the console in front of him and slowly the Voot Runner began to rise, before he pressed a second, smaller button.

"See you in the past, earth monkeys!" cried Zim. "Well, perhaps one of you, anyway!" he added, just as the canopy sealed shut over him and Gir, who waved happily at the crew.

Everyone in the bay turned to look at Fry.

"Hey!" he complained with a stern look on his face. "How come everybody always looks at me when someone says something like that?"

At first it looked as though the new engine was simply too massive for the tiny purple craft to support it, even with a large array of tubes and wires attached to it; but the small ship still began to rise, higher and higher, swaying to and fro as the Irken vessel tried to compensate for the extra mass. It rose steadily, angling itself slightly backwards as it did so, just as its new engine exhaust began to glow in a fluorescent blue fashion.

Leela's eye widened.

"Everybody down!" shouted Leela, as she grabbed Fry and Amy and pulled them to the floor behind a counter. Hermes did likewise with the Professor and Dr. Zoidberg just as Zim kicked in the afterburner. Indigo flame washed down onto the floor and was largely dissipated by specially-installed dampeners, although some of the blaze licked at the counters sheltering the Planet Express group. The Voot Runner immediately rocketed up and away like an ancient Earth space shuttle, Zim and Gir screaming within their Irken ship as they shot up through the open roof and towards the stars.

"We've got to get after them!" shouted Leela, leaping out from behind the slightly-charred counter.

"How?" whined Fry. "They took our engine!"

"Not to worry," offered the Professor. "I just happen to have a spare on hand!"

He shuffled over to the edge of the launch pad and pulled a large floor-mounted lever. A pair of bay doors opened in the floor just behind the Planet Express ship, and suddenly a new engine was ratcheted forward and inserted in cartoon-like fashion right into the vessel's exhaust.

"Good as new!" beamed the Professor, who was then swept up by his employees and dragged onto the bridge and strapped down along with everyone else. Leela began to rush through her pre-flight checklist, and then tossed it away.

"Oh, the hell with it!" she blurted out before she yanked back the stick, ignited the new engine, and took off in pursuit of Zim and Gir, who already had a substantial head start.

But out in space, someone was standing in the way, perhaps 30th Century Earth's last, best hope of stopping Invader Zim ...

TBCL