Wally West is the Flash, the fastest man alive, who finds out Aunt Iris has a big secret, she's really from the future. Her grandson Bart Allen needs Wally's help as he has inherited his father's, Barry Allen, the original Flash, super speed and he's burning his life away. After Wally cures Bart they become uneasy partners as Wally tries to teach Bart how to live life in the fast lane. Soon Bart has a secret identity of his own, Impulse, and has to live a double life, super-hero and normal teen, can he find a balance?