Once upon a time, the people of this planet owned high technologies... But for many centuries now, a monstrous catastrophe has thrown civilization into the distant past, and now only Emperor Ajannar and a few of his relatives have knowledge of ancient secrets. Suddenly the “barbarian” planet turned out to be an object the struggle of two warring armies of aliens from outer space - the Tayu humanoids. Emperor Ajannar and his first minister Din intend to enter into an alliance with friendly “aliens” - and with their help resist the invasion. However, for this, people will again have to use forbidden knowledge...