Kroitz was a commander in the Nasgul fleet. In 2287, his ship pursued the traitor Argus, who was seeking sanctuary from the Salla in Federation space. Though Kroitz's ship destroyed Argus's, Argus himself was rescued by the USS Enterprise. Kroitz's ship was badly damaged in battle with the Enterprise, and Kroitz destroyed his vessel in a collision with the other vessel's shields. The attack did not even buckle the Enterprise's shields, however. (TOS comic: "The Return!")