The film opens with Piccolo being attacked and supposedly killed by a group of shadowed fighters. Chi-Chi along with her father, Ox King, and Gohan are attacked by the same group. Goku is out fishing during the attack and after sensing danger, he returns only to find his son has been kidnapped. The group responsible for the attack are Garlic Jr.'s henchmen, and it is later revealed that their reason for kidnapping Gohan was to retrieve the four-star Dragon Ball that was attached to his hat. After gathering the remaining Dragon Balls, Garlic Jr. summons Shenron and he immediately wishes for immortality. Shenron, never having had to grant this type of demand before, grants Garlic Jr. his wish. A furious Goku arrives to try to take back his son, but soon discovers Garlic Jr.'s new power. Kami makes an appearance (which surprises Garlic Jr., who thought that his henchmen had killed Piccolo) and meets up with Goku, and describes a brief history of Garlic Jr. and his father Garlic. Goku then proceeds to try to find Gohan when he is attacked by the villain's gang, whilst Kami faces Garlic Jr.
After briefly fighting, Krillin and Piccolo arrive to help. Piccolo gets revenge for being attacked earlier by defeating Garlic Jr.'s henchman Sansho, while Goku manages to defeat the other two henchmen, Ginger and Nicky. Meanwhile, Kami is getting brutally outmatched by Garlic Jr., until Goku and Piccolo rescue him. With Garlic Jr.'s newly obtained immortality and a new muscular second form, Goku & Piccolo are forced to work together and are able to outclass him. Goku and Piccolo then prepare to fight each other, but then Garlic Jr., angry at his defeat, unleashes his ultimate attack, opening up a portal into another dimension; a void of darkness known as the "Dead Zone", created by Garlic Jr.'s father, Garlic (and the same place Kami banished Garlic in), intending to suck his enemies into the void. Before he could claim victory, Goku's son, Gohan, becomes enraged witnessing his father and friends in danger and releases his latent energy, blasting Garlic Jr. into his own vortex to be trapped for all eternity. Remarkably, in the end of it all, Gohan does not remember a thing of what happened, instead believing that his father defeated Garlic Jr., and with amazement, Goku figures his son is no ordinary boy, but one with a great hidden potential. At the end of the film, Piccolo is seen from above, looking down on Goku and his friends and vows that one day, he will defeat Goku.
A fourth English dub released in Malaysia by Speedy Video features an unknown cast.
^* Furukawa's voice from the original Japanese version is retained in the AB Groupe dub at the beginning of this film, when Piccolo screams and destroys a large rock formation.
^** In the Funimation English dub's credits, Christopher R. Sabat is miscredited as playing the Ox King, a mistake carried over into the Funimation dub of The World's Strongest.OP (Opening Theme):"CHA-LA HEAD-CHA-LA"Lyrics by Yukinojō MoriMusic by Chiho KiyookaArranged by Kenji YamamotoPerformed by Hironobu KageyamaIN (Insert Song):Tenka'ichi Gohan (天下一ゴハン, "The World's Greatest Gohan")Lyrics by Sakiko IwamuroMusic by Takeshi IkeArranged by Kenji YamamotoPerformed by Masako NozawaED (Ending Theme):Detekoi Tobikiri Zenkai Pawā! (でてこいとびきりZENKAIパワー!, "Come Out, Incredible ZENKAI Power!")Lyrics by Naruhisa ArakawaMusic by Takeshi IkeArranged by Kenji YamamotoPerformed by Manna
The 1998 Pioneer release kept the original Japanese music. Funimation's 2005 dub featured a new score by Mark Menza. The remastered releases contain both English audio tracks with the U.S. soundtrack and original Japanese score.
The film was licensed in North America by Funimation Entertainment and the home video rights were sub-licensed to Pioneer Home Entertainment. Pioneer's dub used the same voice cast as the TV series did at the time, and was dubbed by Ocean Productions. They released the film as Dead Zone, and later retitled it Dead Zone Vortex for its television airings. As a bonus feature on the Pioneer DVD, deleted scenes from the original episodes 1 and 9 are shown in Japanese with English subtitles, as these two episodes were yet to be dubbed in full at the time. In North America, Pioneer's dub was released on VHS, LaserDisc and DVD on December 17, 1997.
Once their sub-license expired, Funimation re-released the film on DVD on May 31, 2005, with a completely new dub done by Funimation's voice cast. Funimation also released the movie on November 14, 2006 as part of a movie box set subtitled "First Strike", also containing The World's Strongest and The Tree of Might. It was later remastered and released in a Double Feature set with The World's Strongest on Blu-ray and DVD on May 27, 2008. The film was released to DVD again on November 1, 2011 in a remastered box set containing the first five Dragon Ball Z movies.
AB Groupe, a French company that holds the license to the Dragon Ball franchise in most of Europe, licensed and dubbed the movie, which they re-titled In Pursuit of Garlic. This dub featured a voice cast that was unknown for years, but it is now believed that English-speaking voice actors in France were involved with this dub. In Pursuit of Garlic aired on TV in the Netherlands, the United Kingdom, and Ireland, and was sold on DVD in the Netherlands by Bridge Entertainment Group. Speedy Video, a Malaysian-based company, released the film on Video CD, here subtitled The Vengeance of the Demon King. Speedy also released the Pioneer English adaptation on VCD. Both the AB Groupe and Speedy dubs are notoriously known for inaccurate translations (e.g. Piccolo was called "Big Green" in the AB Groupe dub) and dialogue that did not fit the mouth flaps.