Written by BRIAN K. VAUGHAN Penciled by BRANDON PETERSON Cover by BRANDON PETERSON Bound together by their unique genetic heritage, the mutant members of the X-Men have become more than just a team - they've become a family. But even the strongest family can be ripped apart by tragedy... and the death of one of their own leaves the remaining X-Men struggling to deal with the loss. And even before a moment of silence can pass, the mysterious Mr. Sinister arrives, intent on giving the X-Men a lot more to mourn! Collects ULTIMATE X-MEN #46-49. 112 PGS./ALL AGES