Young actors come and young actors go, but Michael Caine is forever and movies are the better for it.

This is demonstrated once again in "Flawless," a thoroughly rewarding 2007 heist caper that has inexplicably been released with virtually no promotion to support it.

The film is set in London in 1960 and takes place largely within the walls of London Diamond, a venerable company that has practically cornered the world's supply of the precious stones.

Caine's co-star is Demi Moore, who acquits herself quite respectably in the old master's company. She plays Oxford-educated American Laura Quinn, the sole high-ranking female executive at London Diamond. Middle-aged, single and seemingly without a social life, she has devoted herself to her career only to be repeatedly passed over for promotion. Worse, she finds out that she's about to be fired and blacklisted by the thoroughly nasty men who control the company.

It is Mr. Hobbs (Caine), the very observant night custodian, who informs Laura of her plight. He then invites her to join in a plan to extract sweet revenge. Like a fine diamond, his scheme is seemingly flawless, though it isn't until near the end of the film that we learn just how clever it is. We also learn -- and this is one of the plot's most surprising and delicious turns -- the true target of Hobbs' plan. Even his accomplice is largely kept in the dark.

Supporting roles are inconsequential with three exceptions: London Diamond's crusty chairman (played by Joss Ackland), the company's chief insurer (Derren Nesbitt) and an investigator named Finch (Lambert Wilson) who tries to figure out who relieved the company vault of countless pounds of uncut stones and how he or she got them out of the building undetected.

Finch casts a suspicious eye on Laura, but an agreeable electricity elevates their relationship a notch. He respects her intelligence. He recognizes her defenselessness as a woman among clubby rich white men, and there is a hint of sexual attraction as well.

"Flawless" is directed by Michael Radford from a screenplay by Edward A. Anderson. The story is told as an extensive flashback after an opening setup that might just as well have been discarded. There also are a few puzzling bumps in the narrative thread. But those are minor defects in an otherwise taut and absorbing movie.

Moore, who probably is known more for her figure than her acting, hides her curves in unflattering '60s-era business suits for "Flawless," and ends up projecting a persuasive blend of grit and vulnerability. But, more than anything else, it is Caine's understated portrayal of the principled, pragmatic and deceptively abject Hobbs that makes "Flawless" a sleeper well worth a trip to the theater.