Image Credit: Courtesy of Prime Invincible is finally back for season 4, and the Prime Video series isn't just another superhero animation. Packed with jaw-dropping twists, emotional drama and brutal action, the successful show follows teen Mark Grayson as he steps into his destiny as a superhero - only to discover that heroism isn't as simple as it seems. So, when exactly does the fourth season come out? Throughout the first three seasons of Invincible, fans watched Mark evolve from a naive teen into a battle-scarred hero forced to make impossible choices.