Rana Mitter assesses the shortlist for this year's Booker prize and speaks to nominee Jhumpa Lahiri. Joanna Bourke and Paul Schulte examines the history of chemical warfare and our ambivalence to it. Plus Colin Thubron and Artemis Cooper celebrate the publication of the long awaited final instalment of Patrick Leigh Fermor's account of his journey from the Hook of Holland to the Bosphorus and beyond.