Directed by brothers Anthony and Joe Russo, the sequel to the hit 2011 film is believed to be based on the acclaimed comic-book storyline of the same name in which writer Ed Brubaker revealed Captain America's World War II sidekick Bucky Barnes didn't die in the 1945 explosion that left the superhero in suspended animation in a block of ice. Instead, an amnesiac Bucky was rescued by the Soviets, fitted with a bionic arm and programmed to serve as an assassin known as the Winter Soldier. The secret is revealed in the present day only after he seemingly killed the Red Skull and launched a terrorist attack on Philadelphia.
Created in 1989 by Mark Gruenwald and Kieron Dwyer, Crossbones -- along with his new lover Synthia Schmidt, daughter of the Red Skull -- plays an important role in the "Winter Soldier" storyline.
Grillo, who'll next be seen in "Zero Dark Thirty" and "Gangster Squad," joins Chris Evans, Sebastian Stan, Anthony Mackie, Scarlett Johansson and, according to Variety, Samuel L. Jackson and Cobie Smulders in the sequel.
"Captain America: The Winter Soldier" opens April 4, 2014.