Sasha and Puck and the Brew for Brainwash, Paperback/Daniel Nayeri

Sasha's father sells magic potions. There's only one problem: his potions don't work. In order to keep the family shop open, Sasha has to take magic into her own hands. When greedy Vadim Gentry orders a potion of persuasion from the Juicy Gizzard, Sasha is suspicious. But it's not until he slips it into Papa's drink and orders him to sell the shop that Sasha realizes the problem: If Papa says no, Vadim will know their potions don't work, but if Papa says yes, they'll lose the shop forever Either way, Sasha has a big problem to fix.