The most obviously distinguished of the three, in terms of both writing and observation, is of course Paul Theroux's Nurse Wolf and Dr Sacks. Theroux's wonderfully supple portrait of the neurologist Oliver Sacks is taken as the doctor walks through Manhattan with his patient Shane, who has Tourette's Syndrome. Shane runs, darts, breaks into tics verbal and physical - "Hi, hi, hi", "Hup! Hup!" - while Dr Sacks ambles and observes, in a state of self-effacement which Theroux slyly undoes with his own observations. We watch the watching of this gentle omni-curious man, and we see that he is quietly setting up moments of connection with people for Shane, in line with his theory that solitary behaviour is monochrome, but encounters with others are shot through with different tints, and are far more diagnostically revealing.