From Follett - "Maggie Hope returns to one of her old spy training camps in western Scotland, this time as a teacher. But instead of the tedium Maggie is expecting, she's drawn against her will into another web of danger, this time involving a terrifying biological weapon secretly developed and stockpiled by Churchill for the anticipated Nazi invasion. Maggie's failure to solve a series of deadly poisonings could endanger the lives of the entire British civilian population--but what will be the cost of success?"--Provided by publisher.