“Benedict was a real trooper on the shoot. He was trailing cables and pipes, carrying all the weight of the suit, blinded by the fogging visor and deafened by the compressor that kept the suit inflated. Every time Katie took his helmet off he was sweating buckets. But he never complained. (By contrast, after he’d left – to go to the BBC for the first read-through of Sherlock – we put crew member AJ Nicol in the suit for five minutes for a wide shot and he came out swearing and cursing and moaning.)"