What has happened to Jacques Gaillard? The brilliant teacher who trained some of France's best and brightest at the E´cole Nationale d'Administration vanished ten years ago, presumably from Paris. The mystery inspires a bet, one that Enzo Macleod, a biologist teaching in Toulouse instead of pursuing a brilliant career in forensics back home in Scotland, can ill afford to lose. The wager is that Enzo can find out what happened to Jacques Guillard by applying new science to an old case.