SUDDENLY (1954)
Todd Shaw (Sterling Hayden), sheriff of tiny Suddenly CA, gets a message that the President of the US will be getting off a train in his town on his way to a fishing trip. While Shaw coordinates with the Secret Service and State Police, a trio of assassins, headed by John Baron (Frank Sinatra), and posing as FBI agents, commandeer a home with a perfect view of the train station, and tell residents Pop Benson, his war-widow daughter in law Ellen, and her son Pidge, that they can't leave. All goes well until Shaw and the SS detail chief show up. Then Baron starts shooting, killing the chief and wounding Shaw. The rest of the film devolves into an intense, superbly directed psychological cat-and-mouse game, with Shaw baiting Baron to bring out his inner psychopath to throw him off-guard.

Hayden, one of my favorite actors of the period, is fully up to snuff here. Sinatra, always good as a tough guy, is brilliant in what is probably his best non-singing role. This movie is a little (89 minutes) gem of a thriller.