Circa 2358, she and Doctor Forbus invigilated Cadet Tasha Yar in the Priam IV test, a holodeck training simulation designed to test how Yar considered Prime Directive issues and handled decisions regarding them. T'Pelak and Forbus hypnotized Yar into believing the simulation was real.
They took part in the early stages of the test, pretending to be cadets with Yar on the USS Threnody. The three escaped its destruction in an escape pod but crash-landed on Priam IV. T'Pelak's character was electrocuted and killed in the crash.