Father Koesler's (Donald Sutherland) routine life as a parish priest is suddenly shattered when a bizarre serial killer leaves priests and nuns brutally murdered - the only clue, a black rosary carefully draped in each victim's lifeless hand.
Police detective Koznicki (Josef Sommer) desperately needs the priest's help to solve the mystery, when unexpectedly, in a dark confessional, the psychotic murderer admits his crimes and gives Koesler the answers he needs. But tied to his sacred vows and hampered by the blustery, hard-line Father Nabors (Charles Durning), Koesler must still frantically work against the clock to save the next victim; trap the killer; and stop The Rosary Murders.