Inspector Tom Tyler is making a fresh star in the market town of Ludlow, Shropshire when he receives an early morning call from St. Anne's Convalescent Hospital. A horrifying double murder has been discovered on the grounds and mysterious letters addressed to Tyler and recounting incidents of terrible cruelty and destruction far away begin to arrive almost immediately. It soon becomes clear that Tyler is not only seeking a murderer who may be hiding very close by, but also that the horrors of the war are closing in on this place that is meant to be a refuge for victims of the conflict.