Five years have passed on the planet Tauret since four children and their dragons disappeared. Residents blame dragons for this. Shanna, Tin, Dean and her dragon Artie travel through the portal to Tauret to help find the children. A local boy shows the place where the missing children flew. Shanna makes a planetary-astronomical calculation and finds out that the Octaara Gate has opened on the planet - a gate to the invisible world. Anyone who passes through them becomes invisible. The girl understands that the children cannot return from Oktaara. Her friends move to Tauret to help Shanna. She learns that the exit and entrance from the invisible world are in different places and not everything is simple in the world of Oktaara. Children take risks and enter the invisible world. There they will meet with wizards from the local land of fairies, Nalanya, who are powerless to return the children. But despite this, the children and their dragons will be found. Why the missing children turned into crystal statues in the Jakaranta cave and how children will help them, read in the book The Gates of Octaara.