Le Secret bien gardé !

Goku finally arrives to Earth, but wonders who the mysterious boy really is. The young swordsman asks Goku to speak to him privately. Once he and Goku are out of nearly everyone's earshot, his identity is finally revealed, his name is Trunks, the son of Vegeta and Bulma and he is from the future. He tells Goku of a new threat - in three years, Goku will die of a heart disease, and without Goku, the Z Fighters will be powerless to stop two Androids, from bringing the Earth under their tyrannical rule. He has come to inform them in order to change the future, and gives Goku a special medicine to take when the heart disease strikes him. (Source: Wikipedia)