Cable has made it his one-man mission to preserve all of time itself. But when a disturbance in the timestream sends him back to the recent past, he finds a mutant killer he won't be able to handle alone. Nathan has led teams of X-Men before — but none like this. Get ready for…the Newer Mutants! Longshot! Shatterstar! X-23! Armor! Blink! Doop! But what makes these heroes so uniquely qualified to answer the call? As an unknown enemy targets members of the ancient group known as the Externals, Cable's crew is on the case — and their investigation leads straight to the vampiric Selene! But while the Externals are dying one by one, a familiar face from their number is back — but can Gideon's return be in any way welcome?