A few weeks after Captain America: Civil War blew up the box office, Marvel Comics blew up Captain America. Captain America: Steve Rogers #1, released Wednesday, contains a twist so shocking fans are already calling for a boycott. SPOILER: Captain America has been a double agent working for Hydra this whole time. His mom joined the Nazi-like agency in the 1920s, and Rogers was recruited as a child. The reveal casts 75 years of Captain America comic books in a new light. Here's what you need to know: