Old Kestrel is one of the villagers from Shelling. He is the husband of Aunt Zara, and he is taken off to war when the army comes through, along with his brother-in-law Closti the Clam and his nephew Gull.
When those from the village who went as soldiers come straggling back, among them is Kestrel, bringing along a mentally disturbed Gull. He tells the other children that their father died in the war, and that Gull has somehow been affected by it all. He is kind to them, and in fact is the only member of the village to warn them that the others have decided to kill them all in sacrifice, thinking they had caused an illness that ran through their people, and the unusually large Floods that are just beginning.
Later in the story, Kestrel encounters the family again and helps them by fetching things they need from the village. He's a good-hearted old man, despite being married to that pill Zara.