Brought to London under mysterious circumstances by his tutor, a young boy seeks the help of Sherlock Holmes when his tutor is kidnapped and he himself is threatened with the same fate.
Andrew and Sara help an inspector from Scotland Yard uncover the identity of a murderer and a monster associated with Lord Sommerville, an Assyriologist.
Andrew and Inspector Wyatt help a friend whose father has mysteriously died, whose grandfather is a complete invalid, and whose stepmother is behaving suspiciously with the doctor.
When Sara Wiggins and a friend disappear, Andrew and Inspector Wyatt investigate and discover that the kidnappings are part of a plot against a visiting king.