Corpse Day was an annual day of collaboration between Torchwood and the regular police force, whereby Torchwood would assist the constabulary with a case. According to Owen Harper, tradition was for Torchwood to simply tell the police that the Rift did it.
On one such day, Owen Harper and Andy Davidson came across Glynn Lewis and his Weevil son, Sonny. (AUDIO: Corpse Day)