X-Factor, Vol. 4: Heart of Ice (X-Men) (v. 4)

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? Collects X-Factor #18-24.