The X-Men as a team have always existed to safeguard both the future of mutant kind and that of humanity as a whole. But while the covert team of mutants known as X-Force would like nothing more than to look to the future, they're learning that their past just isn't done with them yet. The squad is catapulted into action when the lethal Legacy Virus goes missing, threatening the lives of every mutant on the planet. Wolverine and the young X-23 must attempt to hold the team together as the brutal, damaged histories of Wolfsbane and Archangel threaten to tear everything apart, starting with each other. Meanwhile, clouds are gathering on the horizon, as the mutant-hating cyborg Bastion places many of the X-Men's greatest threats back into positions of power, spewing the same anti-mutant rhetoric for which they were once known. To protect the future of mutant kind, the members of X-Force must deal with all of their old ghosts.