Secret Kingdom: Midnight Maze: Book 12 by Rosie Banks
Ellie, Summer and Jasmine still have to find one more ingredient to save King Merry from getting stuck as a stink toad for ever. But mean Queen Malice is also about, and she's determined to keep the girls from curing him. Can the girls defeat Queen Malice, find the last ingredient, and get the potion to King Merry before it's too late?