Ernst Lubitsch directed this 1942 film from his own story about a troupe of Polish actors stranded in the Nazi-occupied Warsaw of World War II. It could be his finest achievement, and it’s certainly one of the most profound, emotionally complex comedies ever made, covering a range of tones from satire to slapstick to shocking black humor. The issues, as the title suggests, are deeply serious, but it’s part of the film’s strategy—and the strategy it endorses for its characters—never to openly acknowledge them. Jack Benny, as the leader of the troupe, displays an acting talent never again demanded of him; Carole Lombard, in her last film, is kittenish, slinky, and witty as his unfaithful wife. With Robert Stack and Sig Ruman.