Handy Smurf has created a revolutionary invention: SmurfoMix! However, it's missing a key ingredient, the Green Stone, which is in the greedy clutches of Gargamel. So Handy Smurf and his team set off on a mission to retrieve the famous stone from Gargamel's laboratory, but a fatal misstep causes it to explode, its fragments scattering throughout the Cursed Land. In addition to unleashing into the wild its incredible powers to copy and decompose matter, the Green Stone has set free the evil Stolas, a new order bent on creating a reign of terror.