Superman/Batman: Book One contains two titanic tales of loyalty and unlikely friendship featuring two of the most famous superheroes on the planet--the Man of Steel and the Dark Knight. First, Public Enemies unites the iconic heroes when President Lex Luthor accuses Superman of terrible crimes against humanity and assembles a top-secret team of powerhouse heroes to bring him in. But the World's Finest duo is determined to topple the corrupt president's reign once and for all! Then, Supergirl begins with Batman discovering something strange at the bottom of Gotham Bay, which leads him to a mysterious and powerful teenage girl who is bent on destroying Gotham City! Soon she'll capture the attention of Superman, Wonder Woman, and even Darkseid and his Female Furies. What is this strange girl's connection to Superman? How will Darkseid succeed in recruiting her to do his bidding? Who is she, and whose side will she end up on?