In less than two months, Johnny Depp’s Jack Sparrow sets sail on his latest big screen adventure, Pirates of the Caribbean: On Stranger Tides. The fourth film in the swashbuckling blockbuster franchise aims to kick off another trilogy, but is structured as a standalone feature that focuses primarily on Sparrow’s quest to locate the legendary Fountain of Youth.

A second theatrical trailer for the fourth Pirates of the Caribbean flick has been released online, and it focuses on the conflict at the heart of the film: the three-way race between Sparrow, his old frenemy Barbossa (Geoffrey Rush), and the cruel Blackbeard (Ian McShane) to reach the Fountain first.

Captain Jack’s situation in On Stranger Tides is all the more complicated by the fact that Barbossa now works for King George II (Richard Griffiths) – and that Jack’s former flame Angelica (Penélope Cruz) is also Blackbeard’s daughter. Throw zombie pirates, beautiful but deadly mermaids, and Sparrow’s beloved Black Pearl – which has seemingly been commandeered by Blackbeard and his men – into the mix, and it’s just another day for Captain Jack Sparrow.

The latest theatrical preview for Pirates 4 also offers a bit more information about how the mermaids – including the not-so-friendly Tamara (Gemma Ward) and mysterious Syrena (Astrid Berges-Frisbey) – fit into the pirates’ scheme to reach the Fountain of Youth.

Check out the new Pirates of the Caribbean: On Stranger Tides trailer (via Yahoo! Movies) below:

While the first trailer for On Stranger Tides painted the movie as being your standard Pirates of the Caribbean flick, this new preview makes it look all the more focused and fast-paced than the last two entries in the series. It also appears that director Rob Marshall and screenwriters Ted Elliot/Terry Rossio have struck a better balance between moments of humor (courtesy of Depp in most cases) and the darker elements of the film’s plot – especially in comparison to filmmaker Gore Verbinski’s last Pirates pic, At World’s End.

Squid-bearded Davy Jones may have looked quite impressive in the last two movies, but McShane as Blackbeard already looks and sounds like a far superior villain for Sparrow and Co. to match wits with. As fans (like myself) of the actor’s turn on HBO’s Deadwood can attest, McShane can have quite the intimidating screen presence – even when he’s not dropping f-bombs every other line.

On Stranger Tides will of course have plenty in the way of explosion-friendly set pieces, supernatural creatures, sword fights, and Depp getting up to his usual Sparrow-style hijinks. The film’s production design looks as impressive as ever, and this should be one of the rare upcoming summer tenpole pics that’s actually worth checking out in 3D – especially since it was actually shot in that format.

It seems that moviegoers are in for a much more swiftly-paced and overall less bloated cinematic ride this time around; that’s especially good news for those who recall how much the last two Pirates movies tended to drag on.

Pirates of the Caribbean: On Stranger Tides hits regular, 3D, and IMAX 3D theaters around the U.S. on May 20th, 2011.