Mark of the Monkey (3) - S1.E49

As Luna and Torunka manage to find Regulus, Luna notices he has a Minus Staff stuck in his leg, causing him to hear the opposite of what Luna says and become distrustful of her. Luna manages to steal one of the foot soldier’s Minus Staffs to negate the one on Regulus, and when he notices she is a Signer, he decides to help them.