Needing a tear from a mermaid to complete the Fountain of Youth ceremony, each team travels to a mysterious bay to lure the creatures into a trap. Blackbeard's crew reach the bay first - but do not fully understand the creatures' beauty ... and vicious cannibalism!
After a great number of the crew die, one single mermaid is left behind - she is captured and prisoned inside a glass coffin. The Preacher Philip takes a shine to her and protects the mermaid along the next step of their journey to find two chalices from a shipwreck that once belonged to royalty (also needed for the ceremony).
Jack, knowing the location of the wreck, is sent alone on the perilous journey. He reaches the wreck (balanced precariously on a cliff edge) to find Barbossa lying in wait. The chalices have been removed - the Spanish got their first.
Together they break into the Spanish camp to steal the cups, but are soon captured. Jack escapes up a palm tree and makes his escape, taking the chalices with him. Barbossa is picked up by his crew. Joined by Gibbs, Jack returns to Blackbeard.
Needing the mermaid's fresh tear, the dodgy Pirate captain plans to tortue her - until it is clear that she has feelings for the Preacher. Philip is stabbed and, believed to be dead, taken away. She still doesn't cry. They all leave.
After a little while Philip awakes and returns to rescue her. She cries a tear of joy - and instantly Blackbeard shows up to steal the tear. She blames Philip for the trick.
They head off to find the entrance to the Fountain in some caves. With a little magic, a portal opens in the cave ceiling - and the men jump through it. In a different realm, they are suddenly confronted by Barbossa and his crew - who is solely after Blackbeard's blood. Both crews fight - finally Barbossa manages to stab both Blackbeard and Angelica with his poisoned sword.
The Spanish show up with a different objective - to tear down this abomination of the Fountain of Youth. Meanwhile, Philip, mortally wounded, escapes the realm and returns to rescue Serena the mermaid. She brings him into the sea with her to live forever.
With a few drips of the fountain remaining, Jack fills both cups -- he offers the cup of life to Angelica -- but Blackbeard takes it instead. Jack suddenly remembers that he might have made a mistake - the cups were switched. Angelica can now live for longer, while Blackbeard ages quickly and dies "Last Crusade" style. Angelica is irate.
A little later, Jack and Gibbs walk along the shoreline where Gibbs says that Jack should have taken some of the water - but Jack says he doesn't need it. Gibbs shows Jack his stash from Blackbeard's ship -- all the ships in glass bottles including The Pearl.
As it ends, Jack rows Angelica to a deserted island to maroon her, leaving her with just a one shot pistol. She shoots at him, but misses. Jack quickly rows away.
Apparently after the credits there is an extra scene with Angelica, but it's always only ever for a few seconds and takes about 20 minutes of credits to sit through, so I didn't bother this time! If you saw it then let us know!