hides aboard a truck and is transported to the Jade Emperor, the temple at the sacred mountain of T'ai Shan. There, he is recaptured, but Hsien-Ko decides to keep him alive as a hostage to ensure the Doctor's good behaviour should he show up again. She has also stolen the TARDIS to ensure that the Doctor cannot escape. The Doctor returns to Shanghai, where he finds his way to Woo's nightclub and is reunited with Romana. Woo has heard Kwok's name mentioned in a conversation about the movement of a Japanese brigade, and the Doctor takes them to question the colonel in charge, only to be recaptured by Hsien-Ko. Hsien-Ko takes Romana to the Jade Emperor as another hostage while leaving Mr Sin to guard the Doctor and Woo, but before leaving she tells the Doctor that she is the daughter of Li H'Sen Chang, a former servant of Magnus Greel and that despite appearances, she is over 65 years old. The Doctor and Woo overpower Sin and their guards, but as they escape K9 reports that he has detected the presence of uranium in the vicinity. The Doctor realizes that Hsien-Ko intends to use a nuclear reactor to increase the power of the Dragon Paths, and works out how they are being used. The arrival of Greel's Time Cabinet must have irradiated the young Hsien-Ko with chronon particles, explaining her slow ageing; and the zygma beam which powers the Cabinet is still intersecting Earth's natural telluric currents, enabling Hsien-Ko to tap into them and move instantly along their paths. If Hsien-Ko focuses a nuclear reaction through the telluric currents, she will short out the zygma beam and release fifty years of accumulated energy—enough to use the Dragon Paths to travel anywhere in time and space. But in doing so she will cause the Time Cabinet to materialize here and now, creating a temporal paradox centred upon Hsien-Ko herself and unleashing Magnus Greel upon the world of the 1930s. Romana is surprised when Hsien-Ko allows her to move freely about T'ai Shan, but Hsien-Ko is convinced that her cause is honourable and believes that Romana will come to understand this if she is allowed to find out the truth for herself. Hsien-Ko is using a nuclear reactor she has constructed from the stolen Japanese supplies to supplement the mountain's natural piezoelectric qualities, the very qualities which first drew the Time