In 2358, the Pegasus was commanded by Captain Erik Pressman, and included Ensign William T. Riker, on his first assignment out of the Academy. In that year, the Pegasus was assigned to conduct a test of a phasing cloaking device, in direct violation of the Treaty of Algeron. During the test, an explosion occurred in main engineering, resulting in heavy casualties. Several members of the crew, including the first officer and chief engineer, mutinied in an attempt to shut down the illegal test. Pressman, Riker, and seven other crewmembers fled the ship in an escape pod. Not long after departing, the plasma relays were ignited, and made it look like the ship had exploded. No wreckage was found, and the vessel was believed to have been destroyed by a warp core breach. In fact, the Pegasus was