After being diagnosed in her early 40s with metastatic melanoma – a rapidly fatal form of cancer – journalist and mother of two Mary Elizabeth Williams finds herself in a race against the clock. She takes a once-in-a-lifetime chance and joins a clinical trial for immunotherapy, a revolutionary drug regimen that trains the body to vanquish malignant cells. Astonishingly, her cancer disappears entirely in just a few weeks. But at the same time, her best friend embarks on a cancer journey of her own – with very different results. Williams’s experiences as a patient and a medical test subject reveal with stark honesty what it takes to weather disease, the extraordinary new developments that are rewriting the rules of science –and the healing power of human connection.