For the regular universe counterpart, see Carol Marcus.

In the mirror universe, Carol Marcus was a Terran scientist and the mother of David Marcus. Together with her son, she invented the Genesis Device, an invention capable of terraforming barren worlds into Class M planets, however, her work was cancelled by Emperor Spock before it could enter its third phase in fear of provoking the Klingons into an arms race. Instead she was commissioned by the Emperor to work on the Memory Omega project, an endeavour responsible for preserving the scientific and cultural knowledge of the Terran Empire after its downfall. (VOY novel: The Mirror-Scaled Serpent)

Alternate continuityEdit

In an alternate continuity, Marcus was the human commander of the Regula One Research Station in 2285. Her son with James T. Kirk, Dr. David Marcus, also worked along side her on the station. Following David's death in 2285, Carol believed incorrectly that Kirk had killed David, but apparently still had feelings for him. When the ISS Enterprise visited Regula One, Kirk wanted all information regarding a crossover into the Primary Universe. Carol's feelings for Kirk mean that she readily because gave the research data to him. However, after transmitting the data Kirk ordered the station destroyed, saying the Terran Empire considered her loyalties suspect. (TOS comic: "The Mirror Universe Saga")