Goku, the only strong enough to stand up to the androids, suffers a heart attack in battle and retreats. Goku is saved, and his recooperating from his illness. The androids run amuck in the cities while the Z warriors await Gokus recovery. News comes about a time machine discovered that matched that of Trunks's. It is investigated, but all that is found is and empty shell of an unknown being that has been newly hatched.
Piccolo is in the sky palace with kami.
Kami guardian of earth senses the mysterious being from the shell. Piccolo asks what he senses, but Kami only tells that the world does not need a god right now, but a super powered being to face the catastrophe that is to come. Piccolo and Kami fuse, and the two become one once again. The being hatched from the time machine show itself. It shows that it has been literally absorbing humans, and introduces itself as cell, other wise known as android 21.