Naming of moons underworld, and Nix (a respelling of Nyx), mother of Charon, is the goddess of darkness and the night. Kerberos is a giant three-headed dog who guards the entrance to the underworld. The fifth moon is named for the river Styx that forms the boundary between the worlds of the living and the dead. The name of Eris's moon Dysnomia was suggested by its discoverer Michael E. Brown, who also suggested the name of the dwarf planet. The name has two meanings: in mythology Dysnomia (lawlessness) is the daughter of Eris (chaos). However, the name is also an intentional reference to
The Dog It Was That Died a 'policeman' but actually another spy, Hogbin is assigned to investigate the circumstances of Purvis's suicide attempt, and in particular a letter he posted to Blair before his first attempt. Hogbin is the polar opposite of Blair – doggedly determined, prone to panic and seeing conspiracies at every turn. Pamela Blair, wife of Giles. She runs a donkey sanctuary, occasionally appropriating her husband's study as an operating theatre for her injured charges. She is having an affair with Blair's boss; a fact about which both she and Blair are entirely open and unconcerned. "The Dog It Was That Died" has