Not everyone who is close to death — or thinks they are, at least — has a “near-death experience”. But those who do often hallucinate that they leave their bodies, meet otherworldly beings, or see bright flashes and tunnels of light. Those who take the psychedelic drug dimethyltryptamine, or DMT — a compound found in the hallucinogenic Amazonian brew known as ayahuasca — experience many of the same things.