Continuing their search for the legendary and powerful Map of Gneima, Oliver, Gemma and Nikko travel to the Desert of Riakalah in Sanzotur. There they follow their mysterious clues to the giant Arch of Gaya. Meanwhile, the kingdom of Rootan is taken over by another – one more evil and wicked than King Portenza. A terrible plague descends on the kingdom, and all are afraid of what will happen to them next.