Iain Sinclair is renowned as the great chronicler of our city and in his new book he strikes out on a series of walks to take the temperature of the capital from the pinnacle of the Shard, to the outer limits of the London Overground, from the Thames Estuary to the ruins of Olympicopolis. As ever poignant, thought-provoking and wry – this is at once a critique, a memoir and a love letter to London. Here to chat to Iain about the book is Keggie Carew, author of Dadland, which won the Costa Biography Prize last year.