The end of Norman Osborn's Dark Reign rocks his team of killers! The ruthless Wolverine foe known only as Mr. X joins the Thunderbolts! He's just in time to help the squad target former team member Songbird, but she has plenty of tricks up her sleeve -- and enough experience fighting dirty to know that attack is the best form of defense! But who will answer her cries for help? What is the Black Widow's deadly game? And how are Nick Fury and his band of Secret Warriors involved? Then, Osborn targets Power Man and Iron Fist! Is he trying to kill them, recruit them -- or both? Plus: It's on as the Thunderbolts set their sights on 1950s heroes the Agents of Atlas! And as Osborn begins his insane siege of Asgard, his team of psycho killers will clash with the Mighty Avengers! Collecting THUNDERBOLTS (1997) #132-143 and SECRET WARRIORS (2009) #7-9.