Stingray (1964 TV series) to HO". The process of designing and making the puppets took four months and each of the main characters was sculpted in duplicate to allow two episodes to be filmed simultaneously using both puppet stages. The likenesses of some of the puppets were inspired by real-life actors: Titan was based on a young Laurence Olivier and Surface Agent X-2-0 on either Claude Rains or Peter Lorre. Troy Tempest was modelled on James Garner at Gerry Anderson's suggestion. Atlanta Shore has been likened to Lois Maxwell (who voiced the character) and Marina to both Brigitte Bardot and Ursula Andress. "Stingray" was
The Lodger (Doctor Who) of International Rescue," which is a reference to both Captain Troy Tempest from "Stingray" and International Rescue from "Thunderbirds", both series created by Gerry and Sylvia Anderson. Steven Cooper of "Slant Magazine" also saw a reference to the Emergency Medical Hologram from "", as the Doctor continued "Please state the nature of your emergency." "The Lodger" made up the seventh and final production block of the series along with "Amy's Choice". The read-through for both episodes took place on 17 February 2010 in the Upper Boat Studios. The story replaced another one, "The Doctor's Wife", when the latter was pushed