Lunar connections and allusions pervade the episode. With Dixon away to the Cape, Mason turns his attention to his new assignment—assisting Maskelyne in his attempts to establish observations of the lunar distance as the preferred means of obtaining longitude at sea. He is unnerved by Maskelyne's account of his former assistant and the erratic and paranoid behavior of the lunatic astronomer. Maskelyne is wary of political enemies at home and conspiracies on the island concerning his appointment and the benefits of being related to Clive of India, a prominent figure in the East India trade. Mason's own paranoia and melancholy wax as he remains on the island, but he manages to maintain enough perspective to falsify a flattering interpretation of the Maskelyne's horoscope during one night of drinking at Maskelyne's favorite bar, The Moon.