The mysterious Miss Pertwee has left behind a legacy no one can find. In life, she was hooked on mysteries and spy stories - this is how she patterned her life. Peter Hatch and company need to track down meagre clues and determine what her legacy was - and where. Aided by a former soldier, Thekla Nevraki, and an irascible cracksman named Samu, Hatch follows the clues, one by one, to make the final discovery!