one moment he was the captain of his own pirate ship-a happy place , crewed by obedient eleven-year-olds , except for the girls , who were all a year or two older than nick and who looked especially pretty in their pirate costumes-and the next he was alone on the deck , and a huge , dark ship the size of an oil tanker , with ragged black sails and a skull for a figurehead , was crashing through the storm towards him .