"Huh," Bulma said, surprised, "did you just say androids?"
"Yes I did," Gero calmly answered, "but let us just keep to the matter at hand, shall we?"
Bulma nodded, and turned back to Gero. Gero would have plenty of time he wanted to explain about his research, but only after Piccolo was destroyed. Gero quickly finished entering passwords and disabling the array of rather nasty programs, poised to strike anything that dared try to access the files they were guarding. Gero smiled inwardly, thinking how proud he was when he created these. They were a part of the file itself, you could copy it as much as you wanted, but as soon as you opened it, wham. Game over. The ideal security programs.
A few hours later, Kami entered the room, asking if there was anything he could help them with, since Chiaotzu and he took a break. Big mistake. Caught between two scientists, he found himself being completely drained for information, particularly about the Mafuba attack (A/N original DB, Piccolo Saga) and Kami's gas-form technique. They then turned back to their notes, implementing their newly acquired information in it. While the two scientists were discussing the details, Kami took this opportunity to sneak out of the room.
The next day continued like this for the most part. After a good night's sleep, Yamcha and Chichi were training and while Yamcha's power level was higher, Chichi more than made up for it in fighting skill. Yamcha had taught her how to use Ki blasts and she taught him in return how he could improve his stance. Chiaotzu and Kami were also getting along fine. Chiaotzu had managed to modify his Psychic Hold attack so that it would immobilize beings like Kami, and it took Kami increasing mental effort to break free. Chiaotzu might have hit his limit power level-wise, but his psychic abilities were improving fast. Bulma and Gero, however, had finished their preparations, and impatiently waited for Roshi to arrive.
At a quarter past noon, the sound of an airship landing in the backyard made the two scientists run for the door. Before Roshi was out of the ship, he was trampled underfoot by them, scanning the ship for Piccolo's arm. They noticed Oolong standing there with something wrapped in a sheet. Noticing the look in their eyes, Oolong quickly threw it at the scientists, and Bulma and Gero ran off to the lab to study it. Kami, Yamcha, Chichi and Chiaotzu had followed the scientists as soon as they went for the door, and helped Roshi back up.
"Yeah, nice seeing you too," Roshi remarked, brushing footprints off of his clothes, "Wha- wait a sec, wasn't that Dr. Gero?"
"Chiaotzu and Chichi as well," he continued, "but what's Kami doing here? I heard he rarely gets off his Sanctuary."
"You know who I am?" Kami asked, surprised at being recognised.
"I spent three years at Korrin's Tower catching the Holy Water." Roshi answered, "Korrin and I used to talk a lot during rests."
"But anyway," Roshi said, turning to Yamcha, "you promised me an explanation, and from what I've seen so far, I'd like one right now."
"Okay, follow us," Yamcha said, leading him inside, "we'll tell you everything that has happened."
While the Z Fighters were filling Roshi in on the events of the past few days, Bulma and Gero finished their analysis on Piccolo's severed limb. Although it had mostly decayed over the past few days, they still managed to get the information they needed. They took samples of its RNA and DNA structure, and compared them to Kami's, which they had taken when he had walked in on them. They smiled when they turned out to be nearly identical. It meant that if it worked on Kami, it would work on Piccolo also.
In the meantime, Roshi wasn't feeling all too well. Having a sixth sense for Goku, he knew something had gone terribly wrong, but this exceeded his wildest fears. Most of the strongest fighters he knew were dead, and with Piccolo guarding the dragon balls, the only way to get them back was by defeating him. And Krillin had already been wished back once, so he was gone for good. Roshi sighed.
"Master Roshi," Yamcha asked, "we were wondering if you wanted to fight alongside us again. You used to be the strongest on the planet."
"Well I don't have much of a choice, do I," Roshi said, "Okay, I'll do it. I'm a bit rusty though, it's been a while since I last fought."
"That's great," Yamcha exclaimed, "and between me and Chichi, we'll get you up to fighting shape in no time."
"Come to think of it," he added, "Chiaotzu, would you teach us all how to fly? I don't imagine Piccolo letting us all climb to Kami's Sanctuary and us defeating him afterwards too."
"Sure thing," Chiaotzu replied, happy to be needed for once, "I'll see you all in the training room."
"Excuse me, Kami," Bulma said through one of the installed speakers, "we'd like you to come to the lab. There are some more tests we'd like to run."
"Great," Kami muttered, shuddering at the prospect, "I hope they finished testing my regeneration rate though."
And with that, they all left. Chichi, Yamcha and Roshi followed Chiaotzu to the training room for flying lessons, while Kami went to Bulma and Gero's labs. Kami couldn't wait until this whole thing was over with. He longed back to when he stood on his Sanctuary, looking out over the Earth, back in the days Piccolo was still imprisoned in the pressure cooker Mutaito (Roshi's sensei) put him in using the Mafuba attack. But, unfortunately, dwelling on the past never saved the present before. Steeling himself, he pushed a button, making the doors slide open, and walked into the main lab.
A few more days passed like this. Bulma and Gero systematically tortured Kami to make his body achieve it's gas-form state against his will, Yamcha, Chichi and Roshi training for the upcoming battle and Chiaotzu honing his psychic skills. Then, one day, Bulma's voice came through the speaker.
"Hey guys," Bulma said, sounding tired, "we finished working on that thing you wanted. Get everyone to the living room please."