Collects X-Men Prime #1 ; Uncanny X-Men (1963) #322-326; X-Men (1991) #42-45, Annual 95; X-Men Unlimited (1993) #8.The X-Men have just averted the Age of Apocalypse, but the threat of Onslaught is right around the corner - a villain so powerful he put the unstoppable Juggernaut into a coma! But before the X-Men can learn more about this shadowy foe, they must face Gene Nation, led by the vicious Marrow, and help Magnetos Acolytes battle Apocalypses son Holocaust, who escaped the AoA into the Marvel Universe! Plus, how will the world react when the Legacy virus is made public? Can Rogue handle learning Gambits greatest secret? And did Sabretooths brain damage truly change his personality, or is he a time bomb waiting to go off? All this, and the Xavier Institute enrolls a new student!