As Trunks, Krillin, and Bulma search the strange wreckage of the second time capsule they discover the eerie shell of large, locust-like creature. Whatever was in the capsule is obviously something like they've never seen before. Meanwhile, in the quiet metropolis of Gingertown, an evil such as the world has never seen has arrived. In the wake of this mysterious insect-looking monster, a haunting silence is all that remains of the townspeople. Piccolo, realizing the severity of the danger, convinces Kami of the need to combine their forces. Irreversibly uniting together, the two fuse into one being, a Super Namek! But by doing so, the Earth's Dragon Balls are gone forever.
Piccolo, now strengthened by his fusion with Kami, confronts the hideous beast in Gingertown and discovers his horrible secret. This beast viciously sucks the life force from humans, using their energy to fuel his own being! The monster is known as Cell, and is the ultimate evil creation of Dr. Gero. Created through synthesizing cells from all the great fighters into a single computer-enhanced android.
He has the strength and abilities of all the great fighters including Goku, Frieza, Vegeta, Gohan, and many others. In their conflict, Cell destroys entire armies without effort, and manages to severely injure Piccolo's arm. But Piccolo is a Namekian and cleverly stalls Cell long enough to regenerate his arm. As Krillin and Trunks arrive to back Piccolo up in battle, Cell decides to withdraw for the moment and pursue his primary goal, to absorb Androids 17 and 18!
While Cell has the power and abilities of all of the great fighters, his ultimate form will not be available until he can absorb Androids 17 and 18. In doing this he will truly be without equal. The two Androids, travelling with Android 16, are intent on destroying Goku as they were programmed to do. But now Goku is back on his feet and he comes up with a clever plan of his own. To save the world. he, Gohan, Trunks. and Vegeta will go to Kami's Lookout. There is a room there known as the Hyperbolic Time Chamber where time bends, allowing a year's worth of training in only a day.
As the androids arrive looking for Goku, it is up to Piccolo, the Super Namek, to hold them at bay. And it appears his newly acquired skills will be enough to do so. But just as he seems capable of bringing the menacing duo down a new peril appears on the battlefield. It's Cell! With Earth's greatest hope still training, Piccolo makes the decision to stop Cell from fulfilling his evil plan. But even Piccolo can't stop this creature. It appears all hope is lost when an unlikely ally arrives.
The silent giant, Android 16, boldly walks on to the battlefield and makes the bold claim that he is just as strong as Cell! And in an instant it appears he's telling the truth, as he pelts Cell with a blur of intense blows. But Cell is devious, and through some crafty trickery manages to sneak up on the unsuspecting Android 17 and absorb him. Now Cell is transformed and the tables have turned.
Vegeta has the upper hand in the battle with Cell, but his pride will be his downfall. Cell throws down an irresistible challenge to Vegeta: allow Cell to absorb Android 18 and become complete, and then fight Cell in the ultimate challenge. Despite Trunk's warnings, Vegeta falls for it.
Android 18 should have been deactivated by then, but Krillin is starting to fall in love with Android 18 and does not deactivate her. Instead she ends up being absorbed by Cell who becomes Perfect.
Goku and Gohan continue to train, while Vegeta picks up the challenge of fighting Perfect Cell only to be defeated. Trunks jumps in to give Krillin a chance to rescue Vegeta. Trunks has amazing power and strength beyond the strength of Cell. But it takes more than strength to win a battle. He has traded speed for power and cannot catch his enemy. Cell defeats Trunks but gives our heroes another chance. Cell is going to host a World Martial Arts Tournament in 10 days where he will fight each of Earth's warriors, including Goku.