In 1141 two monks arrive in Shrewsbury from Winchester, where their abbey has been destroyed. Brother Humilis, who is gravely ill, and Brother Fidelis, who is mute, must seek refuge in Shrewsbury. From the moment he meets them, Brother Cadfael senses that something deeper than their common vows binds the two brothers. As Brother Humilis's health fails, Cadfael faces a poignant test of his discretion and his beliefs as he unravels a secret so great it could destroy a life, a future, and a holy order.