Ben and Polly's first trip by TARDIS takes them to the 17th-century Cornish coast, in the era of smugglers and pirates. There, the Doctor receives a clue to the location of hidden pirate treasure – making him a target for the vicious captain Pike. His interrogation is delayed when a smuggler named Jacob Kewper contacts Pike, erroneously believing him to be a fellow smuggler; when Pike learns that the local Squire is the head of a smuggling ring, he decides to impersonate a smuggler, learn the location of the smugglers' hoard, and then kill them all and acquire the goods for himself. The Doctor and Kewper manage to escape, but Kewper goes straight to the Squire with news of the hidden treasure. The Doctor and his friends have only one ally – Revenue man Josiah Blake, who has been investigating smuggling in the area but now finds that all hell is about to break loose. While Blake rides for the militia, the Doctor struggles to decipher the clue he's been given, knowing that only by locating the treasure himself can he bargain with the pirates and smugglers and prevent a battle which will inevitably result in the deaths of innocent townsfolk.