Relive the monumental origins of Marvel's Sentinel of Liberty, retold for the modern age -- with new secrets revealed! As Captain America is born, so does the rise of the Red Skull begin…but who is the mysterious Agent X?

Relive the monumental origins of Marvel's Sentinel of Liberty, retold for the modern age -- with new secrets revealed! As Captain America is born, so does the rise of the Red Skull begin…but who is the mysterious Agent X?