The Dead Zone is also a Dragonball Z
movie that was released in America in 1997 and takes place a little bit before the first episode of the TV
In this movie, Garlic Junior, whose father was refused role as guardian of the earth, comes to the planet to exact revenge for his father's being locked away in a hell dimension.
Garlic's minions kidnap Gohan, Goku's son, not to draw out Goku, but rather because the child's hat has the four-star ball on it. Garlic's men succeed in gathering all seven Dragonballs and summon the Eternal Dragon. Garlic Junior then wishes for immortality, and the dragon grants his wish before vanishing and spreading all seven balls over the Earth once again.
Goku eventually comes to the aid of his dear son, and with the help of his then nemesis Piccolo, and his best friend Krillin, they waylay Garlic. But then he opens a gateway to the "Dead Zone," and only Gohan's hidden power that is released when he becomes very angry is enough to seal Garlic away right along with his wicked parent.
Piccolo lets Goku, Gohan, and Krillin live to fight another day, and all is well... for the next few days, at least.