Set against the vibrant backdrop of a 1960s-inspired, retro-futuristic world, Marvel Studios’ “The Fantastic Four: First Steps” introduces Marvel’s first family as they face their most daunting challenge yet. Forced to balance their roles as heroes with the strength of their family bond, they must defend Earth from a ravenous space god called Galactus (Ralph Ineson) and his enigmatic Herald, Silver Surfer (Julia Garner).