Lost City of the Jungle

Lost City of the Jungle 1946 is a Universal movie serial.

Lionel Atwill died of cancer and pneumonia while filming this serial. Atwill was playing the mastermind villain, Sir Eric Hazarias, a foreign spy chief. Universal could not afford to throw out the footage already filmed so they were forced to adapt the serial. First, another villain Malborn, played by John Mylong, who was originally just a servant of Sir Eric was introduced as the boss of Atwills character to take over most of the villain requirements of the film. Secondly, a double of Atwill was used to complete his remaining scenes. The double was filmed from behind and remained silent. The villains henchmen were filmed repeating their orders back to the silent double and stock footage of Atwill was edited in to show a response.Lost City of the Jungle was Universals penultimate serial the final Universal serial was The Mysterious Mr. M, which was also released in 1946. ........

Source: Wikipedia