Cynnes Tarth has a secret.

The people have forgotten what lies within the fog, but they do remember to be careful. Don't let the children play too much in warmlake. Don't go into the forest. Most of all, don't show any interest in the brinlins that live among the reeds. But Marim, a young Tessilari stranded among these people, doesn't know the rules. In hopes of establishing herself as a healer, she agrees to help Tassin, a boy with the hunger, doomed to die. When she recognizes his affliction for what it is, she must deduce what no one can tell her if she hopes to save his life.