Mermaids are drawn to man made light. So Jack, Blackbeard, and Angelica travel to the light house to ignite the fire. There is a big container of whale oil stored above the fire. The oil slowly comes down into a bowl and is lit on fire. Blackbeard: "Can you make it work?" Crewman: "Made by the English. . . Let's not get our hopes up." There is a large lens that is used to project the fire's light across the bay and point it to the bait, which brings us to our next step.
The man made light is directed onto a small rowboat, filled with the usual suspects: Scrum, Philip Swift, a zombie quartermaster, and some other terrified crew mates. All they can do is sit helplessly in their little dingy, wait for the mermaids to come and eat them, and hope that some how the crew will be able to bring down the mermaids before too many people die. "There'll be mermaids upon us within the hour, you mark my words. And we're the bait. . . they snatch a sailor of a boat or off the deck of a ship, have their way, and then the sailors are pulled to the bottom and drowned and eaten." This couldn't get any better could it?
Mermaids are attracted to singing, so to make sure that they appear, the quartermaster commands Scrum to sing. Not sure which he fears more, the zombie quartermaster or the wicked mermaids, he timidly begins to sing. "My heart is pierced by Cupid; I disdain all glittering gold. There is nothing can console me But my jolly sailor bold. Come all ye pretty fair maids Whoever ye may be Who love a jolly sailor bold That plows the raging sea." At first it seems as though nothing is going to happened, but then a mermaid slowly swims up to their boat and rests her head on the side. She sings the song with them, and Scrum falls instantly into her love trap, despite his friend's warning. They are about to kiss when she tries to attack. The others are too quick and strike at her first. And then all out war breaks loose.
The rest of the crew is either in other rowboats, fighting the vicious sea creatures or on the shore with nets to capture them. Those in the boats are trying to attack the mermaids (who were there because they were attracted to the light and singing) and drive them to the shore. Blackbeard commands his ship with his super cool sword so that fire is blasted towards the mermaids. They're smart creatures though and they fight back powerfully, using seaweed to drag sailors into the depths of the sea with them. Jack, realizing how dangerous the situation has become, calls out, "Retreat, I say!" But sadly, Jack's not captain, Blackbeard is, and he has other plans, "Cowards! Back in the water! There be no refuge on land! Mark my word!" He begins to shoot towards anyone trying to escape.
Jack, of course, saves the day with some ingenious yet ridiculous plan. He climbs up back to the light house, narrowly escaping being taken by mermaids. Once on top, the bangs on the container holding all the highly flammable oil until it creaks. He then jumps out of the tower in just enough time too keep himself from being toasted. As he plummets down towards the water, the light house explodes, sending everything in the bay into chaos and forcing the mermaids to finally retreat. But the crew manages to capture one mermaid, Syrena, thanks to Philip Swift. Jack climbs out of the water, exhausted. "" Success! All thanks to Jack, as usual.