GAMORA

In Warlock Vol. 1 #15 (1976), Thanos sent Gamora away on an errand with a private reason for wanting her gone: he was preparing a programme of stellar genocide, and he knew his adopted daughter well enough to be certain she would walk out the moment she learned of it. On the way, Drax the Destroyer attacked her ship, and then the story simply stops — the Warlock series was cancelled with that issue, mid-plot.

The next time readers saw her, in Avengers Annual Vol. 1 #7 (1977), she was already dying. Told in flashback, the missing chapter finally surfaced in outline: Gamora had uncovered the genocide plan exactly as Thanos feared, confronted him with it, and he had beaten her and left her for dead. Adam Warlock reached her in time to hear the warning and draw her soul into his gem, which is where she remained while the universe moved on without the scene that explained any of it.

The confrontation itself was meant for a Warlock #16 that never shipped. Jim Starlin had begun the issue — a few pages were pencilled — before the cancellation killed it, and the pages were lost. So the single most important decision of Gamora's life, the moment the deadliest woman in the galaxy chose against her father, exists in continuity as a summary delivered by its victim on her deathbed, rather than as a story anyone got to read.