The Marsh Lane potMarsh Lane has twenty little houses, and the river Reed runs past them. Most years the river stays in its bed, but one wet spring it filled a cellar. Drying it out and mending the walls cost ten pretend coins, a big bill for one family. Before any plan, two houses out of twenty flooded in a wet year, so eighteen families paid nothing and two paid ten coins each. Only luck decided the bills, and nobody did anything wrong. A risk is a chance of a costly surprise. Then a careful neighbor named Wren said, "Everyone puts one coin in a pot each year." All twenty families dropped in a coin, so the pot held twenty coins. In the first year two cellars flooded and each bill was ten coins, so the pot paid both and was empty. Otis made a claim, and Wren checked that his flood was real. In year two everyone paid in again and only one cellar flooded. The pot paid ten coins, and the other ten stayed in the pot for next year. In year three, three cellars flooded, and the pot held ten left over and twenty new coins.