It was still overcast and rainy, but not yet dark. Traffic was slow. He watched below him as a station wagon passed, then a convertible, a moving van, and a small truck advertising EUCLID’S DRY CLEANING AND DYEING. The great name reminded him of the right-angled triangle, the principles of geometric analysis, and the doctrine of proportion for both commensurables and incommensurables. What he needed was a new form of ratiocination, and Euclid might do. If he could make a geometric analysis of his problems, mightn’t he solve them, or at least create an atmosphere of solution? He got a slide rule and took the simple theorem that if two sides of a triangle are equal, the angles opposite these sides are equal; and the converse theorem that if two angles of a triangle are equal, the sides opposite them will be equal. He drew a line to represent Mathilda and what he knew about her to be relevant. The base of the triangle would be his two children, Randy and Priscilla. He, of course, would make up the third side. The most critical element in Mathilda’s line—that which would threaten to make her angle unequal to Randy and Priscilla’s—was the fact that she had recently taken a phantom lover.