Leonie, a young girl from Los Angeles, falls into a state of clinical death after an overdose of drugs. In a strange way, she finds herself in a special world, where she meets a supreme being - the Blue Angel, who has taken the form of a wise and beautiful woman. She tells Leonie that a terrible demon named Sulpa, as old as the Universe itself, is rushing into the world. And that this demon has a way to overcome time and space. If Sulpa commits a monstrous crime in prehistoric times, in the Stone Age, he will gain such strength that nothing in our 21st century can stop him from taking over the world. Only two people can stop the demon - Leonie and her distant Cro-Magnon sister Ria from the Stone Age. They are destined to meet, because they both find themselves in a knot of times in which the past and the future are intertwined...