After their adventures in Ancient Egypt, Luì and Sofì just want to rest, but a new threat looms over the Earth. A magical spring hidden in the jungle holds the key to undoing all the world's spells, but if tainted, it can turn the Earth into a barren, lifeless wasteland. Viperiana has discovered this and with the help of her faithful Serpe servant has already started mixing enchanted potions in the spring that turn the water purple; it will only take a few days for everything to be irreversibly poisoned. A fight against time begins for Luì and Sofì who, together with Pongo's assistant and accompanied by the guide Serenino and Tara, daughter of the Pesantosi tribal chief, will have to decipher the map that will lead them to the magical spring and foil Viperiana's diabolical plan . But they have to be careful, because an unexpected enemy lurks among them.