Rufus dreamed that he was Caius, contemplating a lattice of spheres in a space of some unspecified higher dimension, trying to decide if a certain kind of hyperplane lay entirely within the gaps between the spheres, or if it would be forced to intersect some of them. He swung the hyperplane back and forth, agitated, hunting for a solution. But the problem was not purely mathematical; Caius was sure that the answer would determine whether or not the police would be able to prove that he had murdered Linus.