 Papa Smurf sends Bigmouth after more wood to the fire, and while he's out, the four Smurfs leave the water, a magic formula is applied to it, and four Smurf costumes are thrown to make the giant believe that the Smurfs have dissolved into soup.When Bigmouth returns and drinks the soup, he becomes a blue monster (due to the formula), and Papa Smurf tricks him into believing that was the effect of drinking Smurf soup and that Gargamel knew all along.Right then Gargamel arrives.