When the greatest ruler of the Western world decides to establish diplomatic relations with the powerful ruler of the East, he makes a truly royal gesture. Charlemagne decides to send as a gift to Harun ar-Rashid the most amazing animals that can only be found in his domain: a huge aurochs, polar bears and - a wonder of wonders - the legendary unicorn. Of course, all these creatures must first be obtained, but for this the king has faithful servants. The honor of finding rare animals and delivering them halfway around the world, from Aachen to Baghdad, fell to Sigwulf, a Saxon prince without a kingdom...