Description: On board a 17th century pirate ship sailing the ocean waves, a crew under the command of one Captain Avery are being picked off one by one by a ghostly apparition. They believe it to be a legendary Siren, a beautiful and mesmerizing demon who lures men to their death with its haunting Siren song. She marks her prey before retrieving them with a black spot on their hand, a mark that means certain death. As they are becalmed and stuck in the ocean, all seems lost for the dwindling pirate crew... until three stowaways are discovered with a mysterious blue crate. The Doctor, Amy And Rory find themselves on a 17th century pirate ship whose crew is under attack from a sea siren of some sort. Anytime one of the crew is cut or otherwise sheds blood, a black dot appears in the victim's palm and the siren appears to destroy him. By the time the TARDIS arrives, there is only a handful of them left. The ship's Captain, Henry Avery, is surprised to find his son Toby is a stowaway. Soon, Toby and Rory are victims of the siren but the Doctor and Amy have a surprise in store when they learn where they really are.