Pirates of the Caribbean: Dead Man's Chest begins with Will Turner and Elizabeth Swann offering a knee-jerk defense of their friend. When a new villain sneeringly refers to "Jack Sparrow," Will and Elizabeth both snap back, "Captain... Jack Sparrow!" It's an indication of loyalty -- fierce, built on an assumed trust and much good faith, yet quite fragile. By the end of the movie, selfish motivations loom large, bonds may be broken, and there might even be a betrayal waiting around the corner.

If this sounds dark, it's no mistake. What's most surprising about this sequel to 2003's smash hit, Pirates of the Caribbean: The Curse of the Black Pearl, is how much more serious it feels. Black Pearl won viewers over because it was so light on its feet, even as it tried to enthrall its audience with believable feats of derring-do. Dead Man's Chest has plenty of its own goofy moments and occasions of bemused humor, but as the movie goes an opposite route of the first movie -- it's about trust crackling rather than trust cementing -- it adopts a tone of more gravitas.

Other factors, both helpful and not so helpful, contribute to this effect. One other surprise to me was how the filmmakers decided to make this movie a conscientious middle movie of a trilogy. The third Pirates movie went into production immediately after this second one, and instead of making them both standalone adventures, Dead Man's Chest ends, cliffhanger-style, to lead into the following film. It follows the route of the Back to the Future and Matrix movies, where the surprise hit status of the first film led to the next two being planned simultaneously. The middle movie in such scenarios demands to be darker, and this one's no exception.

However, in planning such a story, the writers (Ted Elliott and Terry Rossio, of the first film) had to sacrifice a key ingredient of what made the first movie so much fun -- the budding chemistry of our heroic trio. The most popular character, Johnny Depp's Captain Jack Sparrow, unfortunately suffers the most here -- he's given no real straight man to play off of and is often doing funny things by himself, off to the side. He spends most of the movie getting scared and running away from stuff. And as his character is required to now alienate his former pals Will (Orlando Bloom) and Elizabeth (Keira Knightley), he seems so much more disreputable that it's less fun to be around him now than it was the first time. Jack still has his moments, but his tendency to get lost in his own world, disregarding the others around him, has lost some charm along with its novelty.  

The movie becomes even more scary when it introduces its special effects piece de resistance -- the Kraken. This gigantic tentacled monster eats whole ships for breakfast, and, without mincing words here, it looks spectacular. More realism means yet even more gravity, as it becomes difficult to squeeze in moments of offhanded levity when humongous tentacles are laying waste to the sailors and pirates. Almost as convincing as the Kraken is the heartless (literally) Davy Jones (Bill Nighy, disguised under the makeup) and his crew of, for lack of a better description, undead crustacean pirates. Davy has a squid for a countenance, only with more tentacles, which move around on their own and even help him play the pipe organ.

Dead Man's Chest, practically by design, is not as full of fun as The Curse of the Black Pearl; director Gore Verbinski is hoping that viewers will hop on for the ride and develop a genuine concern that will pay off in the next movie. Thankfully, he didn't skimp on spectacle -- not only is the Kraken an amazing piece of work, the movie features a three-man swordfight on a runaway mill wheel that's the definition of good ol' summer movie action. The movie's unexpected turn at the end lends it some weight -- perhaps not enough to call the movie a satisfying mix of style and substance from start to finish, but it's just the right amount to make me feel very impatient about waiting to the see the next chapter.

(Released by Walt Disney Studios and rated “PG-13” for intense sequences of adventure violence, including frightening images.)

Review also posted on www.windowtothemovies.com.