It turns out that our heroes need Jack Sparrow, last seen leaping into the Kraken's gullet, in order to convene the council of the Pirate Lords. So, with Barbosa as example and guide, they set out to bring Sparrow back from the dead (and yes, he is dead), so setting off on what must be the most epic and magical sea story to be filmed since "Jason and the Argonauts."
It must be acknowleged that there is lots about the plot and storyline that don't make any particular sense, but you get caught up in the action and the sheer glory of the effects. For example, Barbossa's return to life is never explained. Tia Dalma says that it was easier to bring him back than Jack because "he was un-dead," but he was pretty clearly sincerely dead at the end of the first film, and no explanation as to why she would have wanted to bring him back, if indeed she was even responsible--. And there are other such flaws, but suspend your disbelief and go along for the ride.
The plot is carried by the core cast, with nicely piratical permutations of alliance and betrayal as the dynamics between Elizabeth, Wil, Jack, and Barbossa shift and work out. Chow Yun Fat is largely wasted in a small role as Malay pirate Sao Feng; we do finally get to see Keith Richards in an understated cameo as "Captain Teague" which comes late in the movie, by which time you are tired of waiting for him to appear: the producers should have done the "Alfred Hitchcock" thing and done it early to get it out of the way.
That said, the story works out to a truly epic conclusion resolving the pirates' battle for freedom of the seas, the fate of Davy Jones and his crew, the Wil-Elizabeth-Jack triangle, and (more or less)the ongoing rivalry between Sparrow and Barbossa. I don't expect to see another picture in this franchise: I think it has been brought to a satisfactory ending. STAY TO THE END OF THE CREDITS!
Recommended, if you liked the preceeding installments. If you did, you will not be disappointed. Very intense action and violence, although no gore.