It is the far future. The artificial intelligences created by humanity are now gods, and mankind mere ants who scrabble in their shadows across a million worlds. The Lords of the Great Houses on the ever-night Moon of Hexator are suspected of the murder of one of their own. And merchant William Roxley, once a magistrate-priest, is unwillingly coopted to uncover the truth behind the killings. With only the help of his naive young assistant and a brutish robot bodyguard, the man they call 'Sweet William' digs into the Moon's eerie existence. A collapsing society where many strange, terrible things are happening under night's unsettling cover. Hexator is a place where nothing is what it seems, perhaps not even William Roxley himself!