In 1868, with his army officer father suddenly posted to India, and his mother mysteriously "unwell," fourteen-year-old Sherlock Holmes is sent to stay with his eccentric uncle and aunt in their vast house in Hampshire, where he uncovers his first murder and a diabolical villain.

Kidnapped and taken to China, teenage Sherlock finds himself plunged into the heart of a deadly mystery. How can three men be bitten by the same poisonous snake in different parts of Shanghai? Who wants them dead, and why? The answers seem to lie in a message hidden in a diagram that looks like a spider's web. But solving one puzzle only leads to an even more urgent question: What has all this got to do with a plot to blow up an American warship?...