(M) **

Director: Rob Marshall.

Cast: Johnny Depp, Geoffrey Rush, Penelope Cruz, Ian McShane, Kevin McNally.

IT says quite a lot for the allure of Depp's Captain Jack Sparrow that despite the second Pirates movie being rubbish, people still lined up around the block for the marginally better third episode.

But now we've got a fourth installment that's as bad as the second and it begs the question: how much longer will people keep going back for a dip in Sparrow's Caribbean?

Make no mistake, On Stranger Tides is down there with Dead Man's Chest in its messiness and levels of disappointment. Even Depp's magic as Sparrow is starting to fade and he can't save a character which is scripted as going from rogue-ish to unlikeable and back again. His few winning moments are certainly not enough to save this wreck.

The MacGuffin at the centre of this fourth voyage is the Fountain Of Youth and after a sloppy intro, Sparrow, his old "frenemy" Barbossa (Rush), his old flame Angelica (Cruz), his former first mate Gibbs (McNally), legendary pirate Blackbeard (McShane) and a legion of Spanish troops are headed for the mythical water feature, albeit in three different fleets.

Along the way there are mermaids, zombies and wavering allegiances to deal with. But who will get there first and will the fountain grant them the eternal life they seek?

By the end of it you'll mostly be thinking "who cares?". The humour has been replaced with a jokey-ness that rarely works and the plot is as unwieldly as Dead Man's Chest, although whereas DMC had too many balls in the air, OST struggles with fewer things to juggle.

The loss of the Orlando Bloom-Keira Knightley relationship surprisingly leaves a hole in this edition (and I never thought I'd write that). Without a romantic angle, the writers have tried to fill the gap with Depp and Cruz, but don't commit to it fully enough and leave Sparrow and Angelica looking worse for the effort. A sub-plot involving a mermaid and a missionary fares slightly better, but again it feels like patch job.

It's not a total loss. There are some good ideas in here, mostly pertaining to the mythology of the fountain and mermaids, and one can only assume they came from Tim Powers' 1987 novel On Stranger Tides, which Disney co-opted for this doomed adventure.

Barbossa is a welcome returnee and his sparring with Sparrow is a treat, while Blackbeard's appearance (as a voodoo-wielding sorcerer/pirate) is tantalising. The whole thing is vaguely entertaining in a "where is this going" kind of way, but once you've taken off the 3D glasses as the lights go up, you'll be left with a feeling of "meh".

Pirates 4 is not a total waste of time but it is a major disappointment. The laughs are few and far between, some bad CG effects mar the better sequences, Depp's performance doesn't have the lustre it once had, and the movie's plot doesn't so much defy logic as tie it up and make it walk the plank.