By discarding several minor sub-plots in "Frost at Christmas", the two major cases were able to be investigated in the one episode, being the pilot "Care and Protection". This novel, and the pilot, introduced the characters of Frost, Mullet, DI Allen (DCI in the series), DS George Martin (Toolan in the series), Sgt. Bill Wells, Sgt. Johnny Johnson, DS Arthur Hanlon (uniform sergeant in the series), DC Barnard, PC Jordan, PC Simms, WPC Hazel Page (Wallace in the series), PC Stringer, newspaper reporter Sandy Lane (Longford in the series), Dr McKenzie, pathologist Drysdale (Simpkins in the series), his assistant Miss Grey and Shirley, Frost's on/off love interest.
