The Librarian was a member of the Man-Machine Ascendancy, the regime that arose to fight mutantkind during the Human-Machine-Mutant War which saw the rise of Homo novissima, successors of humanity, and the near-extinction of mutantkind. The Librarian kept the few remaining mutants in a Preserve.

Once the Homo novissima prepared to assimilate with the Phalanx, uploading their consciousnesses into the Phalanx hiveminds at the cost of the destruction of the Earth, the Librarian began to have second thoughts as to whether "life" as part of a machine consciousness was desirable.

He visited Moira, one of the last remaining mutants, in his Preserve and informed her of what was to occur, contemplating whether or not to kill her and reset the timeline or go through with his plans and arrange for her to taken off-world while he merged with the Phalanx, preserving his knowledge forever. While taunting Moira, he told her that mutantkind had been blind to the rise of the Homo novissima as they had been focused on the Sentinels, who had only existed to buy mankind time to master technology and its own evolution, allowing them to surpass mutantkind.