The framed magazine cover hanging in Lizzie Thornfield's house is a picture from her (Hayley Mills) movie A Matter of Innocence (1967).
Clive wood who plays Johnny in this episode previously appeared in the episodes Blue Herrings and Secrets and Spies.
In addition to Barnaby's dog Sykes, another dog by the name of Oli makes an appearance in this episode. Oli Sykes is the lead singer for the British Metal band Bring Me the Horizon.