When a "Jane Doe" with amnesia and covered in blood steps in front of Cho and Van Pelt's car, Patrick Jane must use all of his skills to discover who she is, her last location and why she lost her memory.
The investigation into a museum curator's death takes a bizarre turn when Castle and Beckett learn he is not the first member of a recent archaeological expedition to die.
Ben and crew of The North Star uncover a device emitting a strange sound; Ryn finds shelter in the home of the local folklore expert.
Maddie rushes to Ryn's rescue after she is taken in for questioning; Ben and Xander return to the deep sea to search for answers, only to be met by an uninvited guest.
The enchanting siren song takes hold of Ben and Decker; Dale must answer for the escalating crime in Bristol Cove.