1873: When the ambitious Doctor Paul Clément takes a job on the island of Saint Sébastien, he has dreams of finding cures for tropical diseases. After witnessing the ritualistic murder of a young boy who was allegedly already dead, he is warned never to speak of what he has seen. Back in fin de siècle Paris, Paul's attentions turn to studying the nervous system and resuscitation through electricity. Paul is told of patients who have apparently died, been brought back to life, and, while they lay between life and death, witnessed what they believed to be Heaven itself. Using forbidden knowledge he swore never to use, he attempts to experience what everyone else has seen, but something goes horribly wrong. When Paul returns to the land of the living, can it be possible that he brings something else back with him, an unspeakable evil so powerful it can never be banished?