In 2151, Krem and his gang of thieves, led by Ulis, rendered the entire crew of Enterprise NX-01 unconscious with a "Trojan Horse" device disguised as an ancient artifact. With the crew no longer a threat, Krem and the other Ferengi boarded the vessel and began looting Enterprise. Unknown to them, however, Trip Tucker was not affected by their device and was able to revive T'Pol.
After Captain Archer was awakened and questioned for the location of a vault which the ship did not have, Ulis ordered Krem to guard him while continuing to load heavy items off the Enterprise and onto his ship. Krem, tired of always being ordered to do menial labor, forced the captain to do his work. As the two conversed, Archer was able to convince Krem that Ulis was not treating him fairly. When Ulis ordered Krem to continue guarding Archer while Tucker, who had been caught by the pirates, lead them to the captain's vault, Krem attempted to stand up to his cousin, but could not follow through.
After being incapacitated by T'Pol with a Vulcan nerve pinch and having the rest of his compatriots captured, Krem was allowed to leave, commanding the ship once captained by Ulis. Before departing, he was warned by Archer that Starfleet Command and the Vulcan High Command would have his ship's design in their database, so they would know if he and his crew decided to start more trouble. Krem assured the captain that they would not return. He then piloted the ship away from Enterprise, ignoring the demands and pleas made by his restrained cousin and cohorts. (ENT: "Acquisition")