This is a fictional account of the interaction between the Marquis de Sade and Choderlos de Laclos, author of 'Les Liaisons Dangereuses', while they were incarcerated together for ten months during Robespierre's terror, a historical fact. It is beautifully and engagingly written, obviously meticulously researched, both funny and terrifying with clever wordplay and evocative use of contemporary vocabulary. The cover says that it helps if you know something about the French Revolution and this made me hesitate: in fact, I learnt a great deal about it by reading it, and was inspired and enthused to find out more about this fascinating - and barbarous - period of history. The sense that the guillotine could fall on anyone at any time was forcefully conveyed. A wonderful book I would recommend to anyone.