Twilight:2000 is a role playing game set in a fictional future, one where World War III began in the late 1990's and eventually slipped into a nuclear exchange, changing society as we know it. Characters take the SSN City of Corpus Christi, the last U.S. nuclear submarine, on a mission of extreme importance through the Dardanelles and the Straits of the Bosporus to Romania to pick up DIA agents and extricate a pair of Soviet scientists.