Sasha and Puck and the cordial cordial

"When Basil Gentry asks for a cordial cordial, Sasha thinks he wants it for his spoiled sister Sisal. A boarding school headmistress is coming to meet Sisal, but Sisal would rather throw a party for her horse. Can Sasha and Puck convince Sisal to be friendly for one whole day?"--Provided by publisher.