Following the destruction of the planet Orelious IX, the Cleponji fell victim to a booby trap of several thousand Aceton assimilators planted by their enemy, the Menthars, concealed in the rubble surrounding the ship.
While in this booby trap, the Cleponji was stripped of all propulsion and weapons systems from the energy drain caused by the assimilators. This left the Promellians unable to move or fight. The ship continued to be lashed with lethal radiation from the assimilators, eventually causing the deaths of its crew, which succumbed to radiation poisoning. The ship remained in the planet's debris field, preserved in near perfect condition, for the next millennium.
In 2366, the Cleponji was discovered by the USS Enterprise-D, while exploring the remains of Orelious IX. The crew explored the ship, and later arranged to have it towed to the museum at the Astral V Annex. It was later discovered that the Enterprise-D was also trapped in the same booby trap that the Cleponji fell victim to. Following the Enterprise-D's narrow escape from the assimilators, the Cleponji and surrounding asteroids were destroyed to prevent any further entrapments. (TNG: "Booby Trap")