King Cold and his son finally land on Earth. The Z Warriors kept their power levels down so they could sneak in closer and avoid sudden detection. Goku is still hours away, so Freeza orders his men to kill all life on the Earth. However, a mysterious teenager with purple hair swoops downs and slaughters all his minions before they have a chance to kill anyone. The youth tells Freeza that he will destroy him, and wastes no time and powers up to a SSJ. The Z Warriors immediately feel this tremendous power and thought of it as Goku's and then proceeded in for a closer look. After a few attacks are exchanged, Freeza is sliced into tiny bits and then vaporized by the unknown fighter. King Cold would not admit to himself that his son could be killed by a mere "monkey," and assumes that the kid's power lies in his sword. Convincing the teen to give him the sword, King Cold attacks. The teen merely catches the blade and proceeds to kill King Cold, despite his pleas.

The unknown youth flies down to the others and tells them to follow him to Goku. He tells the warriors that there would be a two-hour wait until Goku was expected to land. The wait is a long and silent one. Vegeta is stunned and furious with rage after realizing there is yet another Saiya-jin who has surpassed him. Goku arrives in a small Ginyu pod, finally reunited with his friends. The stranger asks Goku to talk to him in private, and Goku agrees. Introducing himself as Trunks, the son of Vegeta, he tells Goku that in three years he will die of a heart disease, and two androids will destroy the world. Goku is upset because he won't get to fight the androids. Trunks explain that Goku need not worry, as he brought an antidote for the heart disease from the future.

While he and Goku are talking, Trunks suddenly goes SSJ and out of nowhere, he lunges at Goku holding his sword in front of him. Goku doesn't budge. Trunks stops, inches before Goku's forehead makes contact with the sword. Trunks smirks, and tells Goku that next time he won't stop. Trunks strikes again and again and again. Each time Goku stops the sword using one finger. Trunks concluded that Goku is just as good as the rumors from his time say he is and is strong enough to defeat the androids.

Trunks gives Goku a specific date and time for them all to meet, and at that time they will face the androids. Then he leaves, but not before telling Goku whom his father and mother are (Bulma and Vegeta) and not to say anything that might endanger his existence and Goku agrees. Goku goes to the group who have been watching the whole thing, and tries to tell everyone what happened but forgets what to say. Fortunately, Piccolo, with his advanced auditory organs overheard the whole conversation and tells everyone everything they need to know but leaving out anything that might endanger Trunks' existence. They all go their separate ways, in order to train as hard as they can for the next three years.

After the three years have passed, everybody goes to meet at the specific point given to them by Future Trunks, now called Miari Trunks since Chibi is born. As it turns out, the island they were supposed to meet on contains a huge city. The Z warriors are surprised to find Bulma there holding a baby (Trunks) in her hands. Goku mistakenly calls him Trunks before Bulma gives him the name, but there is no danger now so everything he has already been born. The Z warriors cannot sense power level of an android, so they must look for the androids with their eyes and ears. Yamcha was the first to encounter the androids, and is surprised to see what they look like, since there was no description given from Miari Trunks. One of the androids punch a hole through Yamcha's stomach and quickly begin absorbing his energy through the red orbs on the palms of their hands. The others eventually find Yamcha because of the rapid decrease in his power and come to his aid. Yamcha is taken back to the original meeting place on the island and given senzu bean, which revives him.

The androids and the Z warriors all go to an island where they could fight and not endanger anyone. Surprising, Goku is winded just from flying. He begins to fight with android #19 and is kicking his butt, but seems to keep getting worse and worse. Eventually the android overpowers him, and begins to absorb his energy. Piccolo is about to rescue him, when Vegeta rams into #19 with a flying kick. The Z warriors realize that the reason Goku is in such bad shape is because his heart condition is hurting him. As it turns out, he has never taken his medicine, because the symptoms never came. Yamcha takes him back to his house, where he is given the medicine, but it seems to have little effect.

Meanwhile, back at the island, Vegeta surprises everyone with the ability to go SSJ. He explains his extraordinary accomplishment and then proceeds to fight #19. Vegeta and #19 fight around a bit and it is clear to see that Vegeta has had the upper hand throughout the battle. Vegeta allows the android to absorb some of his energy but then proceeds to kill #19 with Big Bang Attack. Vegeta turns his attention to #20, but he flees before the battle could begin. Krillin gives him a senzu bean and Vegeta proceeds after the android. The rest of the z warriors soon follow after him. The android notices that the rest of the warriors were there and decides to absorb their energy and then go after Vegeta. His first attempt was Piccolo, but Gohan came to his rescue.

Piccolo wants to return the favor by killing #20. #20 thinks nothing of this because he assumes that Piccolo's energy is no where near his, but his assumption is shortly proven wrong. Throughout this battle Piccolo had always had the upper hand, but thanks to Bulma wanting to see the fight, #20 blasts down her ship and uses this diversion to make his escape to his lab where he could activate the other androids. Miari Trunks rescue Bulma and Chibi Trunks. Bulma quickly identifies the android as Dr. Gero. The next plan of action for the Z Warriors was to get to Gero's lab before he did.

Once Gero returns to the lab he attempts to persuade #17 and #18 to fight the Z warriors. The androids disagree, and don't like being commanded, and say so. The two androids decide to activate #16 despite many warnings from Dr. Gero. #17 and #18 kill their creator without a thought. With the rest of the warriors right out side Trunks tries to destroy all the androids and shoots a blast into the cave which the lab is in, but it has no effect on the androids and #16 is still able to be activated.

The androids fly away to find Goku, and the Z warriors realize where they are heading. Vegeta is mad the androids paid him no attention, and insists on following them despite numerous warnings from Trunks. Vegeta catches up with the androids and confronts them. #18 and Vegeta begin to duel, and #17 is surprised that the Saiya-jin is much stronger than Dr. Gero told them he was. All of the Z warriors return, and Vegeta continues to fight despite Trunks' pleas to stop before they kill him. As the fight continues on, Piccolo notices that the android has infinite stamina, and Vegeta is getting weaker by the minute. #18 begins to land critical hits on the now weakened Vegeta. Trunks cannot stand to see his father in such pain, and intervenes with his sword. However, #18 is so strong that Trunks' sword chips on impact. Piccolo and Tien engage #17, but are beat back easily. Krillin considers helping, but realizes he's no match for the androids. #17 and #18 make quick work of the Z warriors, but do not kill them off. They tell Krillin to give his fallen comrades senzu, because their only true purpose is to kill Goku. #18 kisses Krillin on the cheek, and they all depart.

Piccolo was not very happy with himself and flies off in the direction of Kami's. Krillin notes the direction that Piccolo left in, and speculates that he has gone to recombine with Kami. Since both have an unimaginable hatred for the other, Krillin realizes that the situation must be grave. Back at Goku's house, our hero is still in incredible pain from the heart virus. When Piccolo reaches the Kami tower, he explains to Kami that the world did not need a God, but a superior warrior. However, Kami wants to have a longer look at the situation before he does anything rash, and tells Piccolo to wait.

Krillin and Trunks decide to get to Goku's house before the androids could and inform Chi-Chi of the situation, and that they have to move Goku to a safer location. Goku is loaded into a plane, and they all fly off to Master Roshi's house. In mid-flight the plane receives a call from Bulma saying that another time machine had been found. She faxes over a picture, and Trunks recognizes it as his time machine. He decides that he has to get a closer look, so Gohan, Trunks, and Bulma all head to the reported location. When they reach the machine, they find it covered in moss, and inside there are broken bits of a shell. Trunks has a look at the computer within the machine, and finds that it had departed three years after Trunks' future, and arrived four years in the current timeline. Close to the machine they find an egg capsule that something hatched from very recently. Trunks becomes very worried about the situation, but with nothing else to find, they leave the scene.

Meanwhile, Kami began to fear what was happening down on Earth. Whatever had come out of the egg was now absorbing people left and right. An entire city's population had been extremely decreased by this monster. Kami could not take it anymore, and agreed to merge with Piccolo. He explains to Mr. Popo that it was better to have a warrior in this situation than a Kami, and gives his life to Piccolo. Now possessing a superior intellect and a strong body, Piccolo flies down to find the monster. Finding the monster sucking the life out of the last inhabitant of the city, Piccolo tells the monster to stop. The monster refuses, and begins to do battle with Piccolo. However, Piccolo's new strength is nothing to be trifled with, and he is un-harmed by the monster's attacks. The rest of the Z warriors are confused by this development, as they can sense Vegeta's, Tien's, Piccolo's, and Freeza's power level from the same location. The monster rears back and fires a KameHameHa at Piccolo, catching him off-guard The monster then blurs behind Piccolo and stabs his arm, sucking the life force from it. Admitting defeat, Piccolo requests that the monster explain to him who he was and what he was up to. The monster explains everything to him. Trunks and Krillin arrive soon after this but Cell uses a solar flare to escape and to begin absorbing more life forms.

Upon all of this that was happening Goku had finally recovered from his condition. He seeks out his son, and then Vegeta and Trunks so that they could train for one year in a day. This way they could have a sporting chance against this new foe. After Goku rallies up all the saiya-Jins he uses his instantaneous movement to teleport them to Kami's place. Vegeta and Trunks enter the room of spirit and time first. Down below, Piccolo had divised a plan to try to destroy at least #17 so that Cell could not achieve "perfection." But in trying this he fails and Cell is able to absorb #17. Tien watching from above tries his hand in this game. He use enormous amounts of his energy to try to over power the monster giving #16 and #18 a chance to escape.

But in doing this Tien drains himself and falls to the ground. Goku could not let another one of his comrades fall at the hands of Cell and instantly teleports there. By coming there he realizes that Piccolo is stll alive and safely teleports them both back to Kami's without being further harmed by Cell. Cell cares nothing for them and continues his search #18. Back at Kami's tower Tien and Piccolo are both given a senzu bean. By this time Vegeta and Trunks were ready to come out. Both had enormous power now. Soon after coming out, Bulma comes, after giving a device to Krillin that shut down the androids, with more "saiya-jin" armor for them. All four put it own and Vegeta and Trunks depart to the battle field while Goku and Gohan enter the room of spirit and time to conduct their training.

Cell finds himself surrounded by many islands where the androids could be. So he decides to destroy every one of them to flush the android out. Vegeta arrives on the scene right before Cell is about to destroy the last island containing the two androids. They both fly down to the island where they could begin their fight. Vegeta powers up to a point (USSJ) at which he calls himself "Super Vegeta." Above, Trunks watches as Cell is being beaten from left to right. As the fight goes on Cell knows that he cannot beat Vegeta and asks Vegeta if he would allow him to find the last android so that he could achieve his perfection and become a worthy opponent. Vegeta could never refuse a challenge and allows Cell to do so. At this point Trunks intervines to not let this happen.

Upon being the room of spirit time Goku and Gohan each become stronger. The greates achievement for Gohan is that he is now able to becamse a SSJ. Goku also figures out that he could also power up to an USSJ but he finds this useless in battle since the concentration of energy is too great and makes him slow. Throughout the fight between Vegeta, Trunks, and Cell, Goku and Gohan are unaware since they are cut off from the outside world. Each of them continue to train, pushing each other to max so they would be strong enough to fight Cell.

Krillin had arrived shortly after the battle between Cell and Super Vegeta had began and hound found where #18 and #16 were hiding. Because of his feelings toward her, he destroys the device created by Bulma to shut down the androids. Instad, he tries to help them escape. Trunks by all means tries to prevent this but Vegeta at same wants to prevent Trunks. Anyway, they both become too late, Cell blinds all of them by using a solar flare and absorbs #18.

Vegeta finally has worthy opponent, or so he thinks. Cell has exceeded him in every way. Vegeta last result is his Final Flash attack. It blows away parts of Cell, but because Piccolo's cells within him, he is able to regenerate them. At this point Vegeta could no longer fight, and was going to be killed but Trunks powered up to an USSJ as a result of seeing his father suffer. At the time, Trunks seems to do well, until he concentrates too much power and it begins to slow him down. Trunks is defeated suddenly after this.

Trunks begins talking to himself about if he had more time he could be stronger. And hearing this Cell gives anyone who thinks as themself as a worthy opponent to enter his tournament, the Cell Games, and so, the beginning of something completely new to face.