These are dark times for mutants, and they're getting darker by the day. With the X-Men vanished and presumed dead, Cyclops' new team has only just come together - but now they're about to lose one of their own! Elsewhere, the new Black King of the Hellfire Club makes his move! But what is the truth about the club's involvement in the new X-Men's current quest? Meanwhile, the mutant race faces elimination at the hands of a vaccine that will erase the X-Gene from future generations. As Cyclops' cleanup mission nears its close, all the problems the X-Men have faced will come together! The Hellfire Club's sinister plans, the culmination of the O.N.E.'s assaults on mutantkind and even the inner struggles within the team. It all ends here. This is forever! Collecting UNCANNY X-MEN (2018) #17-22.