Carol Marcus (Alive Eve) was a vital part of "Star Trek Into Darkness," and yet she was nowhere to be found in "Star Trek Beyond." Did she return to Starfleet Headquarters after the death of father? Did she join another ship? While "Star Trek Beyond" made no mention of her whereabouts, co-writer and star of "Beyond," Simon Pegg, recently offered an explanation.
According to i09, who came across Pegg's interview on the Star Trek Podcast, Carol Marcus wasn't in "Beyond" because Pegg wanted to save her for a future film. "We thought rather than have Carol Marcus be not used to a reasonable capacity, let’s just not include her, have her be alive, in canon, and be ready to come back at any time."
In the original "Star Trek" timeline Marcus was a leading microbiologist and the founder of the Genesis Project. She was also the former love of Captain Kirk and the mother of his son, David. It makes sense that Pegg would want her alive in this new timeline, even though she didn't fit the story he was telling in "Beyond."
Pegg had originally planned to explain during the film why Marcus was absent, but those lines didn't make it into the final script. "I think we had some lines to explain her absence in one of the initial drafts that had her going off to start work on the Genesis project and do sort of very, very early research on that, but it didn’t make it into the final cut."
"Star Trek Beyond" is currently in theaters.