London, the 1890s. As magician Li H'Sen Chang captivates audiences, a spate of disappearances amongst young women goes largely unnoticed. But almost upon their arrival, the Doctor and Leela find themselves confronting the feared Tong of the Black Scorpion, and a menace from another time. And there's something fishy in the sewers, too...

The Doctor and Leela investigate the strange events in Victorian London. But a mysterious masked figure lurks in the shadows.

As Li H'Sen Chang works to secure the time cabinet, Leela pursues and investigates his master – the mysterious and murderous Weng-Chiang.

The Doctor and Leela attend Li H'Sen Chang's performance, hoping to confront the magician. But his master Weng-Chiang has other plans…

The Doctor and his allies try to track down Weng-Chiang before he can activate the time cabinet and possibly destroy London.