Baboons, crows, dolphins, elephants... when faced with the death of their own, various species of animals react in fascinating ways. For years, scientists have been describing poignant - and puzzling - scenes. Today, more and more studies investigate where these behaviors come from and what they mean. How do animals react when they discover the body of one of their fellow creatures? Is there a typology of behaviour depending on the biological and social complexity of the species? Are they only instinctive reactions ? Or do they point to an awareness of death, or even to what we call grief ? When a groundbreaking new science attempts to unravel the mysteries of death in the animal kingdom.