"I was researching another book that I was writing at the time when I came across a passage in the Talmud in which the rabbis discussed the possibility of a mouse bringing bread into a house that had already been searched for chometz, leavened bread. The rabbis went around and around whether the house had to be searched again, but in the end, the question was undecided. I knew I had to come up with an answer, and I immediately imagined a troublesome mouse running amok through a Jewish village in the midst of Passover preparations."