Someone called Jacques Derrida, someone called him on the phone, someone who was dead -- this was August 22nd 1979. A mystery, he thought; but it is a mystery that began more than ten years earlier, in 1968, when Derrida, a philosopher, visits Oxford and there, before the very eyes of the Philosophy Sub-Faculty, he dies, several times. Murder, he thought. And so I shall investigate, and begin with a sign that the philosopher says he left within a...