Edward Grainger has been asked to meet a representative of the British government. The man, who calls himself "the Professor", recruits Edward for a mission to China. In China, they infiltrate the Zhong Ma camp, where Edward learns from the Doctor that the camp is used by the Japanese for the purpose of experimenting on humans. Edward and the Professor are here to rescue Mai Ling, an old friend of Edward's. He is rescued by the Professor, and they split up: Edward is to rescue Mai Ling, while the Professor must destroy the samples of blood that the Japanese took from him.