Henry Head is Rivers’s former co-worker and longtime personal friend. While they both worked as researchers in Cambridge, Head intentionally severed the radial nerve in his arm so that he and Rivers could study its regeneration process. Part of the study involved Rivers stabbing Head’s arm with a pin, causing immense pain for the purpose of science and healing, and the ethical dilemma Rivers felt at the time parallels his current dilemma of leading patients to painfully recall traumatic memories for the purpose of processing and moving past them. When Rivers visits Head during his medical leave, Head offers him a job in London as a psychologist for pilots.