A second mystery for thirteen-year-old Agatha oddly – a bold, determined heroine, and the star of this stylish new detective series. Agatha oddlow’s set to become the youngest member of the gatekeepers’ Guild, but before that, she’s got a mystery to solve! There’s been a murder at the British museum and, although the police are investigating, Agatha suspects that they're missing a wider plot going on below London – a plot involving a disused tube station, a huge firework display, and five thousand tonnes of gold bullion….