Complex sentence: Stone makes his last appearance in the show in the episode "Old Friends", which portrays a racketeering case in which the main witness, whose safety Stone had personally guaranteed, is murdered by the Russian Mafia.
Split into simpler sentences: Stone makes his last appearance in the show in the episode "Old Friends". The episode portrays a racketeering case in which the main witness, whose safety Stone had personally guaranteed, is murdered by the Russian Mafia.