Best suck down a cup of coffee -- or two -- before hitting play on the DVD for Unfaithfully Yours, one of Preston Sturges' best films, and perhaps his most undersung.

Rex Harrison was rarely the go-to guy for comedy, but he's put to incredible use in Unfaithfully as a British composer/conductor in America. His younger wife (Linda Darnell) and legion of fans are fawning, and he's obviously wealthy beyond his dreams, with servants galore. We spend the first half of the film getting to know Harrison's Sir Alfred in typical screwball fashion, but at the midpoint Alfred learns that wife Daphne may be having an affair with Alfred's secretary.

Distraught, Alfred imagines three scenarios for dealing with this, while conducting his orchestra. The first, an elaborate plot to murder the wife and frame her lover, is a masterpiece of Hitchcockian proportion. When the show is over, Alfred attempts to carry out the plot, with some of the most hilarous consequences ever put to film.

The darkness of this comedy (which includes Darnell slashed to her death and a game of Russian roulette) probably turned off audiences back in the '40s, and the film was a disaster at the box office. Today it plays just about perfectly, if you can interpret the occasionally thick accents when the dialogue goes into overdrive. Harrison is nothing short of hysterical, and he owns every scene he's in.

Unfaithfully Yours is an uncommonly strange selection from The Criterion Collection, but it's one of Criterion's best movies in recent months. with a generally clean transfer, commentary from a pile of Sturges scholars, an interview with Sturges' widow and an introduction from Terry Jones.

Even if you don't like the classics, you are highly highly encouraged to check out Unfaithfully Yours.