Brock Rumlow, also known as Crossbones, is one of the biggest Steve Rogers foes in the comic books, but he's had a relatively minor role in the Marvel Cinematic Universe so far, and the character was even killed off early in this year's smash Captain America: Civil War -- but was he? Frank Grillo, who has played the supervillain since The Winter Soldier, just raised some serious doubts. Read More »