Alex and his double - Emmanuel Goujon

Alex, a globetrotter, a surveyor of the vast lands of the world and a writer without a reader, cannot die. Centuries pass, death is denied him, time and solitude weigh on him until he meets a character straight out of paradise: Alexandre Dumas. Surrounded by angels, he is bored stiff and prefers to return to Earth, sent by Saint Peter, to understand the reason for Alex's immortality. Always on the move, they travel the world together, from Mexico to Congo-Kinshasa via Cabinda in search of the solution to this enigma.

It is while reading Alex's manuscript, where the mage Taram Uram of the Arid Lands travels through time, that Dumas finally finds a clue...