Landlubbers eager to see the third and (most likely) final installment of "Pirates of the Caribbean" can expect a darker, more serious ride than the previous two trips.Not to say that this movie isn't fun. How could it not be fun, with Johnny Depp's return as the infamous Jack Sparrow? But even Sparrow's antics are a bit subdued, as he and other pirates from around the globe fight for their very survival against the East India Co.A refresher: "Dead Man's Chest" ended with Jack Sparrow being squid -- pardon me, Kraken -- food, and banished to Davy Jones' locker, as a result of one of his less-brilliant schemes. Sweethearts Will Turner (played by Orlando Bloom) and Elizabeth Swann (played by Keira Knightley), along with the mysterious Tia Dalma (played by Naomie Harris) and the crew of The Black Pearl go on a rescue mission to the ends of the earth. They are joined by Capt. Barbossa (played by Geoffrey Rush, who nearly steals the show from Depp), Sparrow's mutinous second from the first movie. They also must try to gather together the nine pirate lords to make a final stand for their very survival.If they don't keelhaul each other first, that is.The rogues of the sea are pitted against Lord Cutler Beckett (played by Tom Hollander), who runs the East India Co. Beckett would like nothing better than to wipe out the pirates, who are interfering with his business. It is clear that the only difference between Beckett and the pirates are the powdered wig, uniform and the thin veneer of "respectability" as fragile as the bone china demitasse he uses to sip his tea. Indeed, the opening scene shows just how hard the government is cracking down on piracy, which I couldn't help but think was a thinly veiled commentary on U.S. politics today. But Beckett also has a powerful, if unwilling, ally in Davy Jones (played by a tentacle-garbed Bill Nighy) and Jones' Flying Dutchman.All these forces converge for conquest of the high seas, with each character double-crossing (and triple-crossing) everyone else. Even the formerly clean-cut Will and Elizabeth get embroiled in the various plots in one-upmanship, even -- it seems -- against each other, at times. There are no innocents in this go-around.As well as the return of a lot of old favorites, Chow Yun-Fat also appears as Capt. Sao Feng, a pirate lord from Singapore; and Keith Richards of Rolling Stones fame makes a brief but memorable cameo as Capt. Teague.I guessed correctly a couple of the revelations about Tia Dalma early on, from hints in the last movie, but "At World's End" still had some unexpected twists and turns. The ending, especially, was a shock.A story on this movie can't be completed without commenting on the special effects and CGI work. The effects are jaw-dropping, particularly through the caverns heading to the ends of the earth and during the final battle, when the Black Pearl and The Flying Dutchman are locked in combat within a maelstrom. I also liked the attention to some of the other, non-CGI details as well, such as the pirate flags (most, if not all, based on historical pirate flags). I know that at least one of the pirate lords has a basis on an actual pirate.Really, my only beef with this movie was I think they carried the joke about Jack Sparrow's multiple personalities a bit too long. I think there could have been better ways to show that Sparrow -- eccentric before -- has gone even closer to that insane edge.While I had initially heard that this would be the last voyage for this storyline, "At World's End" did end on a note that could, possibly, mean another trip. This worries me, because I would hate to see such a fun yarn suffer from sequel-itis. "At World's End" was a fitting, if surprising, conclusion to this swashbuckling tale.E-mail: ahelms@recordpub.comPhone: 330-688-0088 ext. 3153