Alice Eve’s Carol Marcus was originally introduced as Carol Wallace early on in Star Trek Into Darkness, telling Captain Kirk and Spock that Admiral Alexander Marcus had assigned her to the Enterprise.
While Star Trek Beyond wisely kept all of the main Enterprise crew intact, that doesn’t mean every important character from the reboot series returned.
You can see Star Trek Beyond in theaters now, and with Star Trek 4 already in the works, maybe we’ll hear news in the near future about Alice Eve reprising her role.
Despite joining the crew at the end of Star Trek Into Darkness, Carol was nowhere to be seen when the ship had its conflict with Krall.