How does AI compare to a doctor when it comes to saving lives? Doctors are under-resourced and face unprecedented levels of stress, with rising patient numbers and ever developing medical knowledge. But at the same time, they are all too human, prone to racial, class and social biases that affect the care patients receive. Can we improve patient experience and alleviate the burdens of doctors at the same time? In this groundbreaking study, Charlotte Blease reveals how AI, if handled with care, could emerge as the most reliable physician in history. Drawing on interviews with authorities in AI, doctors and patients, Blease shows how technology - despite some resistance - is already making a difference. From diagnosis and second opinions to treatment and aftercare, AI has the potential to revolutionise our healthcare.