One of the unfortunate casualties of iral Alexander Marcus (Peter Weller). Dr. Marcus played a crucial role in uncovering the iral's plot against Khan (Benedict Cumberbatch), but her function in the story is largely forgotten.
The moment Carol Marcus is most known for in Star Trek Into Darkness is when she stripped to her underwear and was gawked at by Captain Kirk. This became one of the most controversial and infamous moments in the film, reducing Carol to a sex object and obscuring the best part who Dr. Marcus was. Carol came aboard the Enterprise with lofty credentials (but under false pretenses) as a genius Science Officer who specializes in Applied Physics and Advanced Weaponry. She deduced the 72 special photon torpedoes the Enterprise was carrying contained Khan's cryogenically frozen followers. Before Dr. Marcus, Nyota Uhura (Zoe Saldana) was the only woman in J.J. Abrams' Star Trek movies' of any significance. Yet the filmmakers blatantly sexualizing Carol Marcus ruined the potential of an otherwise great character to appear in the next Star Trek movie.
Carol Marcus In Wrath Of Khan Vs. Star Trek Into Darkness
Dr. Carol Marcus (Bibi Besch) was introduced in Star Trek II: The Wrath of Khan as the genius behind the Genesis Device. Carol was also a former lover of iral Kirk's (William Shatner), and they had an adult son named David Marcus (Merritt Butrick), who also helped design the Genesis Device. Despite any latent feelings, Jim and Carol's relationship was decidedly in the past, and Kirk was more interested in getting to know David, as well as stopping Khan. Carol didn't return for Star Trek III: The Search for Spock, and David was also killed off as their creation, the Genesis Planet, tore itself apart.
Alice Eve's Carol Marcus was obviously over 20 years younger than Wrath of Khan's version, but she was already a brilliant mind at Starfleet. Carol being the daughter of iral Marcus was a new wrinkle created by Star Trek Into Darkness, which could retroactively be the character's backstory in the Prime Timeline as well. But Kirk and Carol didn't have any love scenes or more than an attraction in Star Trek Into Darkness. Both were focused on the task at hand of stopping Khan and Carol's father, and any type of relationship between Captain Kirk and Dr. Marcus was left as mere potential.
Why Alice Eve Didn't Return As Carol Marcus In Star Trek Beyond
In spite of Carol ing "the family" and being assigned to the Starship Enterprise's five-year mission at the end of Star Trek Into Darkness, she didn't appear in Simon Pegg, later said in an interview that since their story didn't have a use for Carol in "a reasonable capacity, let’s just not include her, have her be alive, in canon, and be ready to come back at any time." Pegg also indicated that an early draft of Star Trek Beyond's script hinted that Dr. Marcus left the Enterprise to do early work on the Genesis Device. Whether Carol was pregnant with Kirk's son when she left his ship is mere speculation.
Yet it's hard to see how the controversy Star Trek Into Darkness sparked with Alice Eve's underwear scene didn't negatively impact Carol Marcus' future in J.J. Abrams' Star Trek movies. Audiences reacted as poorly to Carol being used as eye candy as they did to the film's 'surprise' that Benedict Cumberbatch was playing Khan, after all. The loss of Carol Marcus did allow Star Trek Beyond to create a fantastic new female character, Jaylah (Sofia Boutella), but it's now doubtful Alice Eve will reprise Carol Marcus, or that Star Trek Into Darkness' version of the character will be ed for more than her lingerie.