Zag invents useful gadgets and not so useful thingummajigs. Not to forget the thingummagadgets that he's mostly interested in: inventions whose use is yet to be refined and determined. Zag is (as some 17,000 UK readers now know from book 1) a highly likeable Thingummagadgetician. William and Lucy, the twins, are in luck. They're allowed to accompany their fatherly friend to a very special award ceremony. Zag is to receive the Fellowship of the Galactic Circle from Astral (Defender of the Galaxy of Ideas). Zag had helped Astral to get rid of Eraser the Terrible and thus to rescue the Orb of Brilliance (where all creativity has its root). While our friends get ready for the ceremony, some darker plans take shape. Gurdorpal, revolting ruler of Lurkamungo, is scheming. Not satisfied with having transformed the once beautiful Island of Telijencia into a slimy, festering hell, he's now set his hoards of Lurkwarriors on the loose. Will Lucy and William and their cast of friends be able to help Zag recover the festalpod? Will they get to the juvitree in time? Both they must do if they want to restore the Island of Telijencia to its original beauty and tranquility.