A page torn from Roper Klacks' spellbook, found in front of a rather disturbing mirror in his floating castle. This page holds clues to how to brew potions in his laboratory, but all the 'recipes' are in the form of illustrations. Once she retrieves the page from under the watchful eye of her 'evil mirror twin', April has to examine each of the alchemical essences in turn, to work out which picture corresponds to which essence.
The 'recipes' are:
Clouds + Cobwebs + Catalyst = Invisibility Potion (this is already in the book and allows April to retrieve the page)
Butterfly Wings + Clouds + Catalyst = Light-As-A-Leaf Potion
Clouds + Hot Coals + Catalyst = Wind Potion
Hot Coals + Hot Coals + Catalyst = Explosive Potion
Cobweb + Butterfly Wings + Catalyst = Magic Binding Potion
Obtained from the mirror in Klacks' castle.