The novel is set in Derry in Northern Ireland. Derry , officially Londonderry, is the second-largest city in Northern Ireland and the fourth-largest city on the island of Ireland.
Lucy works in the Public Protection Unit, which investigates vulnerable groups, especially children and women.
Lucy’s mother is referred to as ACC, which is Assistant chief constable. ACC is the third highest rank in all British territorial police forces as well as the British Transport Police, Ministry of Defence Police and Civil Nuclear Constabulary.
This is not important in the novel, but I learn that a month’s mind is a mass for a dead person about a month’s after the person’s death.
We learn some terms in connection with Internet crime. For example, one of the key to find out about the culprits is the sock poppet accounts that David Cooper finds. A sockpuppet is an online identity used for purposes of deception. The term, a reference to the manipulation of a simple hand puppet made from a sock, originally referred to a false identity assumed by a member of an Internet community who spoke to, or about, themselves while pretending to be another person.
Another term is darknet. A darknet (or dark net) is any overlay network that can be accessed only with specific software, configurations, or authorisation, often using non-standard communications protocols and ports. Two typical darknet types are friend-to-friend networks (usually used for file sharing with a peer-to-peer connection)and privacy networks.