Henry Marsh, one of Britain's leading neurosurgeons, has spent years traveling to Ukraine to operate in hospitals that lack the basic equipment his London theater takes for granted. The film follows him through Kiev's Number Two Hospital, where he works alongside Ukrainian surgeon Igor Kurilets, sometimes using a hand drill and a headlamp because the machines he needs are broken or missing. Marsh operates on patients with brain tumors while conscious, talking to them mid-surgery to avoid damaging areas that control speech and movement, and the camera stays close through procedures that do not always end well. One recurring case involves Marian, a young man with a tumor Marsh operated on years earlier, and the film tracks what became of him. Marsh speaks plainly about the mistakes he has made and the patients he has lost, treating failure as part of the job rather than something to hide. The result is a portrait of a surgeon working at the edge of what his tools and his conscience allow.