Star Trek VI: The Undiscovered Country

Klingon General Chang (Christopher Plummer), the Romulan Ambassador, Valeris (Kim Cattral), Admiral Cartwright (Brock Peters) and, in the Director's Cut, Col. West (Rene' Auberjonois) are all conspiring to keep the Klingons and the Federation at war. General Chang used a Klingon Bird of Prey that can fire while cloaked to torpedo Klingon Chancellor Gorkon's (David Warner) ship. Valeris used two stupid, Enterprise crewmen to beam aboard the crippled Klingon ship and assassinate Gorkon and pin the blame on Kirk (William Shatner) . Kirk and McCoy (DeForest Kelly) are exiled to a Klingon gulag but are rescued by Spock (Leonard Nimoy), and arrive at the peace talks in time to expose the conspirators before they can assassinate Gorkon's daughter (Rosanna DeSoto). General Chang's ship is destroyed based on Uhura's suggestion (!) to rig a photon torpedo that can home in on exhaust gasses from the cloaked Bird of Prey. The Enterprise and the Excelsior (now commanded by Sulu) combine to do the Shakespeare-quoting Klingon General in.
Thanks, Evil Ed!