There was a time when the living covered the mouths of their dead with a single coin before their final goodbye. The image of metal glinting over lifeless lips still makes us shiver. It has become a part of our collective subconscious, possibly because the ritual appeared in different traditions, and it survived, although marginally, until as recently as the 20th century.The coins had a purpose: to allow the dead to pay for their passage to the Otherworld. In Ancient Greece, this was the realm of Hades, separated from the land of the living by five rivers. It was a perilous journey, and there was only one guide to take the recently departed to their final destination. His name was Charon, he of the keen gaze.