Long ago, the Je'daii Order was founded on the planet Tython. Studying with wise masters, Lanori Brock comprehended the secrets and teachings of the Great Power - and found her calling, becoming one of the most powerful adepts. But, if Lanori and her parents have great Power, then her brother is completely deprived of this privilege. The young man's training in ancient wisdom ended tragically, and he began to hate the Je'daii. Many years later, Lanori, having become a lone ranger, maintains order in the galaxy. The Je'daii Council summons her on extremely urgent matters. The leader of a fanatical cult, obsessed with the idea of traveling beyond known space, intends to open a space portal powered by terrible dark matter - at the risk of triggering a cataclysm that will engulf the entire star system. For Lanori, a greater shock than the prospect of complete destruction is the decision of the masters - she is entrusted with preventing the catastrophe. But after a stunning discovery, the reason becomes clear: the brilliant and dangerous madman whom Lanori must find and stop at any cost is the same brother whom she has long mourned... and whom she must now fear.

The events of this book take place 25793 years before A New Hope.