No one is safe from the fury of Charles Xavier gone mad. The Sentinels have taken Manhattan; and while these giant robots were designed to hunt mutants, they adapt to any threat--they've even been worthy adversaries for the X-Men, the Avengers, and the Fantastic Four. But now, all that stands between Onslaught's army and the world are Spider-Man, X-Factor, the Punisher, and Green Goblin. What hope do these heroes possibly have against the Sentinels?