This is book 21 of the "Brother Cadfael" series.

This note contains spoilers for the book.

The twentieth chronicle of Brother Cadfael, of the Benedicting Abbey of Saint Peter and Saint Paul, at Shrewsbury. Just, for once, to fully copy the phrase from the front.

Cadfael's son is being held prisoner by one of King Stephen's lords, and NOT offered for ransom. The lord himself has recently turned his coat from the Empress Maude to King Stephen, in despite of his father (who is Robert of Goucester, the Empress' main general). He gets leave to go investigate, traveling with Hugh to a conference. And overstays his leave, and eventually finds and rescues his son (and tells the son who he is for the first time).

And returns to the Abbey. After hearing his story, his Abbott commutes his penance to time served, essentially. In the process of serving his own needs he did good deeds for deserving people, frustrated evil, and even helped shorten the civil war (he participated in keeping the Empress from hanging someone she really shouldn't hang).

I read most of these as they first came out, so very spread out. They stand up well enough in closer order, too. I'm always questioning whether Cadfael's attitudes are justifiable for the period -- I'm not a scholar of the 12th century. Cadfael is pretty comprehensible. He seems to be a very liberal Catholic -- but I suspect few ordinary people really centered their lives around religion; didn't that mostly come later? Now, Cadfael is a monk, and does center his life around religion, but it still doesn't dominate his thinking. He's one who tends to think of god wanting justice, rather than using god to rationalize whatever happens as justice. On the other hand, he and others have been known to let divine justice win over temporal justice, and even to commit things to divine justice. Of course those things always work out right in these books.