Out on the dark and briny sea, a thick fog has fallen. The water is glassy. No wind blows. Four men steer a rowboat toward a larger ship. Judging by their attire and general scruffiness, the men are either heading to a Pirates of the Caribbean audition or are pirates themselves. The ship is festooned with charms that are apparently not warding off whatever ill fate they were meant to ward off, because everyone looks pretty bummed. On board, one man in a tricorn hat looks particularly bummed. His fellow seamen notice. "What's wrong?" asks the least scruffy of them. "Man wounded," answers the bummed man. By now, the rowboat has pulled up alongside and its four sailors have climbed up onto the ship. Everyone looks horrified.
Some of them head to the captain's quarters. The place is heaped to tacky excess with gold and jewels. The Real Housewives of New Jersey would love it. One of the pirates explains: "He slipped in the bilge water, Captain, and fell onto the rigger. His hand..." The speaker trails off. The captain peers pensively out the window before turning to inspect the injured man. "You're a dead man, McGrath," he says. It's barely a nick, but everyone seems pretty doomy about it. The captain grabs McGrath's other hand and turns it over to show a black spot on his palm. "Same as all the others." McGrath starts shaking. The poor old guy looks like he's going to cry. Suddenly, a woman starts singing in the distance. McGrath decides to take matters into his own hands and runs out on deck with a gun. The other pirates try to warn him. "Don't go out there, for God's sake! The Siren is a-callin'!" Captain Fraidybeard closes the door behind McGrath and ties the handles shut with a charm he takes from around his neck. McGrath screams in agony. The Siren's singing stops. The captain and his men venture out and find McGrath's gun lying on the deck. The captain notes that, as with all the others, there was no sign of a struggle. Well, except for his screaming. They fear they'll all meet the same fate unless the wind changes soon.
Something starts knocking from below deck. The pirates gather around a grate just as it swings open, revealing a grinning Doctor with Amy and Rory standing behind him. "Yo ho ho!" the Doctor exclaims with glee. His smile fades a bit at his reception. "Or does nobody actually say that?" Cue the theme music and opening credits.
Next thing you know, the Doctor and friends are in the captain's quarters, trying to explain their presence. "Our sensors picked you up," the Doctor says. "Ship in distress." To the captain, this sounds like gobbledygook, so the Doctor tries to simplify things for the 17th century. "My ship automatically... noticed-ish... that your ship was having some bother." Despite this very convincing testimony, the captain remains suspicious of "the big blue crate" that somehow magically appeared below decks. The Doctor cheerfully introduces his companions and then in a misplaced sense of brotherhood identifies all of them as sailors. The captain has reached his bullshit limit and aims his gun at the Doctor, pronouncing him and the others stowaways. Somehow, no one noticed them or the TARDIS for the eight days they've been sitting out on the windless ocean.