In one compartment of the 11.50 a.m. Sunday train from a north-eastern seaport to King's Cross sit four passengers: a small girl, two nuns in whose care she has been left, and a merchant seaman, who has been looking forward to a solitary gloat over his girlie magazines, and who is at first furious at the invasion of "a bunch of religious maniacs all got up in fancy dress like the Ku Klux Klan". Later there is a fifth passenger: "one of them fat and fortyish women ... running round in short skirts like they're going to kid everyone they're only nineteen." The story of their journey together is told by the seaman, interwoven with his reflections on everything from the absurdity of religion to the desirability of brothels on trains ... and with recollections ranging from early childhood up to the scandalous and ominous events of the previous night.