Wing is dead in the danger room and something is very, very wrong in the Xavier institue. A pulse blows through the mansion, knocking out all of the telepaths, and the remaining X-Men investigate the premisces. They find that they're cut off from the world.
Meanwhile, a Sentinel manages to reactive and drag itself towards Xavier Mansion, eventually cornering the X-Men at the mansion, forcing them to retreat into the danger room while Cyclops and Wolverine destroy the Sentinel. But the danger room may be more dangerous than the robot threat.