The Spanish Prisoner

The Spanish Prisoner is a 1997 American suspense film, written and directed by David Mamet and starring Campbell Scott, Steve Martin, Rebecca Pidgeon, Ben Gazzara, Felicity Huffman and Ricky Jay. The film tells the story of an elaborate confidence game the Spanish Prisoner scam is mentioned, though the actual plot has little if any resemblance to it.

Corporate engineer Joe Ross Campbell Scott has invented a very lucrative, very secret industrial process. While on a corporate retreat at the resort island of St. Estphe, he meets a wealthy stranger, Jimmy Dell Steve Martin, and attracts the interest of one of the companys new secretaries, Susan Ricci Rebecca Pidgeon.Jimmy wants to introduce Joe socially to his sister, an Olympicclass tennis player, in New York and asks him to deliver a package to her. Susan, who sits near Joe on the airplane back to New York, converses with him about how you never know who anybody is, talks about unwitting drug mules, and repeats, Who in this world is what they seem to be? Who? Realizing that he doesnt really know Jimmy, and afraid the package might contain something illegal, Joe opens it on the plane, finding only a book on tennis the 1939 edition of Budge on Tennis in the process he accidentally rips the cover. Once home, Joe buys another copy of the book, to give to Jimmys sister, and keeps the torn one at his office. ........

Source: Wikipedia