In a lovely English village of flowers, Tudor cottages and cobbled streets, Joan Brook works as companion to Lady d'Arcy, living in at the huge mansion with its surrounding park. And the village is not too small for Joan to have found a man whom she can love.

Suddenly the peaceful surface of life is shattered as a poisonous letter is received by the town's most saintly citizen. It is followed by others; no one is safe from the anonymous letter writer. With the letters comes death. In the anguished days that follow, Joan realises that she too is in danger.

For to receive one of these letters could mean the end of her love ... and her life.