Nicola Barker makes her own rules. This is a short novel by her standards but would be substantial by anyone else’s. It is also relatively conventional, being a biographical novel about an Indian sage that sticks fairly closely to the facts, despite featuring an interlude in which we observe a temple by means of a minute spy camera attached to the back of a swift – in 1855. An interpolated story about a devotee includes the sound effect parp-parp! after every mention of the guru’s name. As I say, all quite conventional for Barker.