The surgery scenes are filmed in Europe's oldest surviving operating theatre - dated to 1822 and located in the attic of a church in Southwark, London. In 1962, after 100 years of disuse, the garret and operating theatre were opened to the public as a museum.
Throughout the series there are repeated references to Robert Lessing's experience aboard the Medusa which contributed to his 'affliction' and his corresponding refusal to discuss his trauma. It seems likely, although with some historical complication, that this might be a reference to the wreckage of the Medusa (Méduse), a vessel that struck the Bank of Arguin and inspired the painting 'Raft of the Medusa' by Théodore Géricault. The evacuating passengers of the vessel were lost in a panic; many drowned, some rebelling drunkards were shot by officers, and the rest were forced into cannibalism in order to survive. If Lessing survived his experience adrift of the Medusa, the implication is that he must have engaged in cannibalism.