Whenever Johnny Depp's nutty, rum-swilling Captain Jack Sparrow wasn't onscreen, "Pirates of the Caribbean: The Curse of the Black Pearl" took itself awfully seriously. It was overrated by most, but led to an underrated sequel, the clever and more lighthearted "Pirates of the Caribbean: Dead Man's Chest." Now that "Pirates of the Caribbean: At World's End" arrives to wrap up the trilogy, it's bound to be properly rated by everybody—as a major disappointment.

Not the worst three-quel ever made, "At World's End" nevertheless consistently crosses the line from enjoyably intricate to maddeningly muddled. It keeps the worst traits of its predecessors—the grim tone of "Curse," an overabundance of talky exposition from "Chest"—while abandoning many of their good qualities.

The story, distilled to a basic outline, finds returning characters Will (Orlando Bloom) and Elizabeth (Keira Knightley) joining forces with former villain Captain Barbossa (Geoffrey Rush) to free Sparrow from Davy Jones' Locker so that he can help defeat the pirate-quashing East India Trading Company.

The simple premise drowns under the addition of so many confusing twists, pointless digressions and unnecessary side characters. That makes the movie too busy and impersonal to be much of an actors' showcase, but both Depp and Rush have witty moments. And at least the action set pieces are impressive.

For adult fans, "At World's End" is a letdown, but for younger audiences, it's something worse still. Opening with the hanging death of an innocent pre-teen boy, and featuring a running gag about Captain Jack and Barbossa comparing phallic objects, this ostensible escapist lark pushes the boundaries of its PG-13 rating and just might amass a chest's worth of therapy bills.