Martin Mystery - Season 2 - Eps 4: They Came from Outer Space (2)
M.O.M. reveals Billy's hidden life as Ganthar, destroyer of worlds, before he abandoned his old name, form, and way of life and joined the Center. She sends the gang to trade the captured aliens for Billy, unaware that once the aliens reunite, they will be able to call in reinforcements and destroy the Earth! The only one who can stop them is Billy, but to do that he will have to become Ganthar again— and he might not want to change back.
About Martin Mystery

Title: Martin Mystery
First Air Date: 2003-10-23
Last Air Date: 2006-12-17
Status: Ended
Rating: 6.6/10 (from 61 votes)
Language: FR
Seasons: 3
Total Episodes: 66
Network: Canal J
Genres: Action & Adventure, Sci-Fi & Fantasy, Animation, Mystery
Production Companies: Marathon Media, Marathon Productions, Image Entertainment Corporation
Synopsis
Martin Mystery has a passion for all things paranormal. When he's not at school, this teenage lover of supernatural ooze works undercover for a secret bureau specialising in mysterious phenomena. Together with his older stepsister Diana, Java (a massive caveman lost in time) and Billy (a small green hovering creature), he checks out weird wonders. Martin is always bursting with energy and seldom thinks before he leaps. Diana is his guardian angel – a straight-A student, she brings the brains to their missions. Seen a zombie, alien or ghost? Call Martin Mystery.
Cast

Alexis Tomassian
Martin Mystère

Dorothée Pousséo
Diana Lombard

Sylvain Lemarie
Java des Cavernes

Yann Le Madic
Billy

Laurence Dourlens
M.O.M

Emmanuel Garijo
Marvin (2e voix)

Donald Reignoux
Marvin