“Chinatown” is a Raymond Chandler-style mystery with a hint of post-Watergate cynicism. Lone wolf PI Jake Gittes is more cynical than Philip Marlowe, but still is a man of integrity swimming in a sea of corruption. Gittes is hired by a woman calling herself Evelyn Mulwray to follow her husband. When Mr. Mulwray turns up dead and the real Evelyn Mulwray appears, Gittes finds himself involved in a murder case. The film swept the Oscars in 1974, winning best picture, director (Roman Polansky), actor (a brilliant Jack Nicholson) and actress (Faye Dunaway at her most vulnerable). The DVD is here until the end of April as part of our Scrooge and Marely Coop traveling classics set.