Written by PETER DAVID. Penciled by KHOI PHAM. Cover by PABLO RAIMONDI. With Mutant Town under siege and the X-Cell having taken refuge there, X-Factor races both the clock and their own divided allegiances as they try to stave off the very real possibility of every former mutant being rounded up and imprisoned as a potential terrorist. But will they have to reveal their knowledge of M-Day's secret...and, if so, what will the fallout be? Collecting X-FACTOR #18-24.