Antiquarian Thomasina Bateman is writing a book on the barrows of England, documenting the treasures she finds buried within. When an intriguing letter summons her to the small village of Bewlay, tucked away in the remote countryside, she sets off by train with her assistant a day behind.

Upon her arrival, however, the mysterious man who summoned her is nowhere to be found. Her assistant never arrives. A stubborn landowner refuses access to the barrow, and the locals are wary of this woman who is traveling alone and (gasp!) wears trousers.