The stunning sequel to AVENGERS ARENA! When a group of traumatized teen heroes - including Runaways Nico and Chase - infi ltrate the Masters of Evil, who will break bad? Damaged by their experience in Arcade's Murderworld, these conflicted young superhumans decide to pose as villains, planning to bring the Avengers' rivals down from within. But the longer the teens spend undercover, the more they descend into darkness - and as they start to build relationships with these multilayered criminals, the line between good and evil blurs! What will happen fi rst: joining the Masters for real - or being exposed and killed by Baron Zemo? Will they survive encounters with Madame Masque, Mystique and Sabretooth, and a reunion with Arcade? And what happens when S.H.I.E.L.D. and the Avengers attack? COLLECTING: AVENGERS UNDERCOVER #1-10