A game effort by a decent cast highlights the old-fashioned submarine thriller "Phantom," but heavy-handed dialogue, flurries of melodrama and a silly ending make the whole enterprise sink like a stone.

The film, set during the Cold War (but feeling vastly older), announces that it’s based on the real-life sinking of a Russian submarine in May 1968 that might have led the superpowers to war. But the story that follows is much more Hollywood than history — a stab in the dark by writer-director Todd Robinson ("Lonely Hearts").

Demi, a veteran Russian captain (Ed Harris) whose career was derailed by a tragic incident — cue clunky flashbacks — is given a mysterious assignment aboard a dilapidated, diesel-powered sub about to be sold to China. It happens to be his old ship, a very broad hint that further unhappiness lies ahead.

‘PHANTOM’ Rated: R Opens today at Kapolei 16

"Phantom’s" characters are sketched quickly — Demi is the troubled but humane skipper; his chief officer (William Fichtner) is the loyal supporter; and a technician (David Duchovny), who has brought aboard a piece of hush-hush equipment, is the icy fellow with the sinister agenda. (This sub, you should know, is nuclear-armed.)

The men throw familiar submarine lingo at each other ("rig for silent running") with nary a Russian accent in sight, which somehow feels wrong here.

The film does achieve a few tense moments as the sub, despite Demi’s hesitancy, plays cat-and-mouse with American and other foreign vessels.

Tensions grow. Torpedoes are launched and explode. Sweating men crawl through the sub’s tight spaces. Eventually, there’s a power struggle, and Demi loses control. But he isn’t only tortured with guilt — he’s resourceful.

At the climax, Demi speechifies about how America values individuals and would never launch a nuclear first strike — opinions based, apparently, on a single U.S. visit he made. The bad guys are die-hard believers in the supposed Soviet destiny of world rule.

Our hero needs purgation and redemption, and does he ever get it. The film ends with a groaner of major proportions.

Harris, Fichtner and a few other cast members (Duchovny less so) come off reasonably well, a testimony to their craftsmanship. But a hokey script and stilted direction throw cold water onto "Phantom’s" ability to thrill.