May 12, 767, a city southwest of the Southern Capital, the day of the invasion.
Yamcha had been awake for some time and was ready to leave his mansion when Puar brought the bag containing the fruits of the Tree of Might and Turles' magic scouter.
Puar looks apprehensively at Yamcha and says:
"Are you sure your plan will work? There is someone stronger than Goku, and that being is out there somewhere." Puar says.
Yamcha then says seriously:
"If my plan fails miserably, destroy the base where Androids 17 and 18 are located before they are activated." Yamcha says.
Puar is surprised, he wasn't expecting that, but before he could say anything, Yamcha writes down the location of the base where Androids 17 and 18 were hibernating and orders:
"If my Ki disappears, go to this location and destroy everything within a 5-kilometer radius with Frieza's Supernova. This is an order." Yamcha orders.
Puar, even though afraid, accepts the order and says:
"Okay, if your plan fails, I'll go there and destroy that place." Puar says.
Yamcha picks up the scouter, puts it to his left ear, and activates it.
For a few seconds, the scouter didn't detect any presence, until Goku, Piccolo, Gohan, Krillin, and Tien appeared, their power levels high. But soon other powers were noticed by the scouter, three unknown powers, the weakest had a power level of 65 million and the strongest 550 million.
Yamcha strokes Puar's head one last time, opens the window, and says to Puar:
"If I die, you know what you have to do, show that monster-men are powerful too. The fate of humanity will rest in your little blue cat paws, until soon." Yamcha says.
Yamcha takes flight and heads towards where Goku and the Z Fighters are.
...
Yamcha flies at high speed and arrives at the location where Goku and the Z Fighters were.
Yamcha lands on the ground and finds Goku, who finds it strange that Yamcha is using a scouter and has a bag full of fruit.
Goku scratches his head and asks:
"Why did you bring a scouter and a bag of fruit?" Goku asks.
Yamcha then replies:
"This is a magic scouter; it doesn't have the same limitations as a regular scouter. It can measure any type of power; it happens to be measuring that there are three unknown powers in this city. And they all exceed 60 million power level. Fruit is our trump card; you'll soon find out why." Yamcha replies.
Goku is impressed; he hadn't expected a scouter to be useful after Namek, where power levels rose so drastically.
Goku then asks:
"Is there one of these three that is truly strong?" Goku asks.
Yamcha chuckles slightly and replies:
"One of those three unknowns possesses a power level of 550 million; I think that's enough to give you a minimally enjoyable fight." Yamcha replies.
Goku gets excited and says:
"This will be a good test. I recovered from my heart condition two months ago, and I want to see if the androids are as strong as Trunks said." Goku says.
Yamcha then says:
"The androids aren't all that great; it's Trunks who didn't have a good master. If he trained with Master Roshi, he would become much stronger." Yamcha says.
A little further away, Bulma was with baby Trunks, Yajirobe, and Gohan.
Yamcha sees Vegeta approaching the area through his scouter.
Yamcha then says:
"The last one we need will arrive in five minutes, we're not going to wait for him, civilians are in danger." Yamcha says.
A few seconds later, an explosion occurred in the city, and Yamcha and the scouter pointed out the location where the androids were.
Yamcha then says:
"There are two androids attacking the city! It must be the androids! They're 20 kilometers to the left!" Yamcha says.
Yamcha flies in the direction the scouter was indicating the presence of two androids, and Goku follows Yamcha.
Soon after, Tien and Piccolo follow the path Goku and Yamcha were heading.
...
Yamcha and Goku land on the ground and find an elderly man and a robot; they were Androids 19 and 20.
Android 20 then says in a cold tone:
"Hello Son Goku and Yamcha, I didn't expect you to find us so easily." Android 20 says.
Piccolo and Tien land on the ground.
Piccolo then asks:
"Are these Androids 17 and 18?" Piccolo asks.
Yamcha gives a slight smile and replies:
"If it were Androids 17 and 18, Super Saiyan Goku from Namek would win with one hand tied behind his back. These are other androids, much weaker than Androids 17 and 18 probably are." Yamcha replies.
Android 19 then says:
"Our goal is to kill Son Goku, you are nothing." Android 19 says.
Yamcha then asks:
"Where is the other being?" Yamcha asks.
Android 20 then replies:
"She's coming; first she went to activate the others." Android 20 replies.
The magic scouter begins to show other powers emerging, 375 million, 290 million, 500 million, and 550 million power levels.
Yamcha then says:
"I will not die again! The battle begins now!" Yamcha says.
Yamcha opens his bag and eats a fruit from the Tree of Might, doubling his power level from 8.3 million to 16.6 million, which catches the attention of Goku, Piccolo, and Tien.
Yamcha then hands Tien a fruit from the Tree of Might and orders:
"Eat this or you'll be useless for what we're about to face." Yamcha orders.
Tien ate the fruit of the Tree of Might and his power increased about 100 times, yet he was still below Yamcha, Piccolo, and Goku.
Android 20 looks at Yamcha and asks:
"Is that all you have left as a lifeline?" Android 20 asks.
Yamcha then confidently replies:
"No, the battle is about to begin." Yamcha replies.
Android 20 replies coldly:
"You lost to a Saibaman, I don't know why you're so cocky towards someone as weak as you." Android 20 replies.
Yamcha then says:
"For an old man, you talk way too much. Goku, I'm going to destroy that android, don't interfere!" Yamcha says.
Yamcha clenches his fists, lightning bolts strike the ground, Yamcha's aura turns yellow and his eyes turn green, then he lets out a scream.
Haaaaaaaaa!!!!!!!!
Goku is impressed by this surprise; Yamcha had achieved Super Saiyan form, which means he must also be a Saiyan.
Goku then asks:
"What do you mean??? You're a Saiyan too???" Goku asks.
Yamcha then replies:
"I'll tell you about it sometime, but what we need to do now is defeat the androids." Yamcha replies.
Android 20 trembles before so much power and says in disbelief:
"That wasn't in my calculations..." Android 20 says.
Goku then looks at a dead civilian who was killed by the androids and says in a serious tone:
"Let's fight somewhere else; I don't want to hurt civilians in our battle." Goku says.
The androids agree and fly off, followed shortly by Goku, Piccolo, and Tien.
Yamcha reverts to his normal form and flies away, seeing through the magic scouter that the four androids were in one location and that Android 21 was probably there.
Now things are really going to get interesting, poor Future Trunks, seeing that there are more than six more androids, in addition to Cell.