An elderly Chinese man out for a walk on a January morning in 1937 found the body. Lying on frozen ground beneath a watchtower on the edge of Old Peking, it was covered by a layer of frost. Wild dogs were sniffing at it.

It was the body of a young woman, but not just any woman: she was a ‘laowai’, a foreigner, and she had been terribly mutilated. There were cuts on her pale, bare legs and her face had been stabbed repeatedly.

Horrified, the old man ran to fetch the police. News of the gruesome discovery soon spread and onlookers gathered as Colonel Han, a Chinese detective, together with Commissioner Thomas, from the British Legation, examined the body.