Sir Josse d'Acquin and Helewise are summoned to Southfire Hall, where Josse's elderly uncle, Hugh, lies dying, surrounded by his children. But the pair soon discovers that Hugh's ill health is not the only cause of distress in the house: for Hugh's son and heir, Herbert, has taken an unpleasant new wife, the widowed Lady Cyrille.
Josse and Helewise are distracted by the discovery of an injured young man on the road outside on the evening of their arrival, but the longer they remain in the house, the more they feel that something is very wrong. What happened to Josse's cousin Aeleis, who no one speaks of? Where is Lady Cyrille's small son? And why do they both feel as if the house itself is alive - and threatened by approaching evil?