The movie for August is Suspicion (1941, 99 mins) with Cary Grant and Joan Fontaine, directed by Alfred Hitchcock.
A handsome playboy meets and marries a shy heiress-to-be. But after their honeymoon, she starts believing her husband is a murderer and fears that she could be his next victim.
Joan Fontaine won the Oscar for Best Actress in 1941. Alfred Hitchcock can be seen making his signature cameo appearance about 45 minutes into the movie, mailing a letter at the village postbox.