Irene's family has moved to Evreux, Normandy. Soon after arriving at her
new home, she is approached by a mysterious woman who mutters some
strange words about Irene's mother being in danger, before vanishing
into thin air. It's just the first in a series of unsettling events that
Irene, Sherlock, and Lupin must decipher. The three sleuths questions
will lead them to a secret crypt far beneath the streets of Paris and to
an ancient relic that it is rumored to be worth a fortune. But how far
will someone go to obtain the priceless treasure? Secrets and twists
await the young detectives at every turn as they solve the case of The
Cathedral of Fear.