His wife had worked at jigsaw puzzles like he imagined beavers worked at logs. If you were a beaver and you worked at logs, you probably had a saying or two that you could pass on to others who didn’t normally undertake such things: “Start on the side facing the moon at night — so you can see better — and work your way in.”

His wife said, “Find the edges.” Start with the corners, make an edge, work your way in. Puzzle, meet solution. She had worked in the kitchen where he sat now, the puzzles she did with the…