Siege: Dark Avengers

Collects Dark Avengers #13-16 & Dark Avengers Annual 1. The origin of the Sentry is revealed. Bullseye commits an unspeakable act of murder. Victoria Hand wonders if she's gone too far. And as he plans the final stages of his Siege of Asgard, Norman Osborn begins to succumb to the evil legacy of the Green Goblin.