In 2016, Justin Alexander Shetler, an inveterate traveller trained from adolescence in wilderness survival, made his way to the Parvati Valley, a remote and rugged corner of the Indian Himalayas. There, he spent weeks studying under the guidance of a sadhu, an Indian holy man, living and meditating in a cave. At the end of August, accompanied by the sadhu, he set off on a "spiritual journey" to a holy lake - a journey from which he would never return. This is a riveting narrative centering on the unsolved disappearance of an American backpacker in India.