Charade

The dictionary defines charade as "an absurd pretense intended to create a pleasant or respectable appearance."

There is a connection between the above definition and the 1963 romantic mystery film Charade, produced and directed by Stanley Donen, written by Peter Stone and which starred Cary Grant, Audrey Hepburn, Walter Matthau, James Coburn and George Kennedy.  

Henry Mancini's original song (Charade) was nominated for an Academy Award  (won by James Van Heusen and Sammy Cahn for Call Me Irresponsible in Papa's Delicate Condition).

What a cast!  Hepburn (Roman Holiday), Matthau (The Fortune Cookie), Coburn (Affliction) and Kennedy (Cool Hand Luke) are all Academy Award winners.  Grant (a two-time Academy Award nominee) received an honorary Academy Award "for his sheer brilliance in the acting business," according to his presenter, Frank Sinatra. 

Filmed on location in Paris, Charade tells the story of five former American soldiers who stole a quarter of a million dollars ($2,100,000 today) from the U.S. government during WWII and twenty years later try to retrieve it from a hiding place, each for themselves.  One of them, Charles, is found dead at the beginning of the film.  He had the money, but hid it from the others.  But where?  That is one of the film's mysteries.  

Three of the remaining four ex-G.I.s, Herman (Kennedy), Leopold (Ned Glass) and Tex (Coburn) are desperate to find the stolen loot, but are murdered, by whom?  A CIA administrator (Matthau) and a mystery man (Grant) are also looking for the money.  And they all believe Charles's widow (Hepburn) knows where it is, but she claims ignorance.

At the film's climax, the CIA administrator is really one of the original group of thieves (Dyle) who murdered the other four.  The mystery man is really an American government official (Brian) whose job it is to find stolen U.S. government property.  

Caught between the above two (Dyle and Brian), the widow doesn't know whom to believe.  Finally, she correctly trusts her romantic instincts to believe Brian, who saves her from the murderer (and later asks her to marry him).

And where is the money?  In plain sight.  On a plain ordinary envelope addressed by Charles to his wife are three rare postage stamps worth a quarter of a million dollars.