The practical jokes aboard the holodeck re-creation of the prototype vessel Hyperion have taken a turn for the deadly — the fail-safes have been overridden, and Stevens, Tev, and a shipload of cadets, one of whom is probably responsible for their predicament, are trapped inside. Commander Gomez must help her crewmates solve the riddle, find the culprit, and free them all before more damage is done — and people are killed!