Jessica and Miss Strega are off on an expedition to restock Miss Strega's shop with Brewing Ingredients. They moon-vault up to the Milky Way, meeting a rather fat dragon on the way. When Jess Spells the dragon out of trouble, he tells her where she can get that elusive ingredient Mandrake and also the name of a dentist who will supply Dragons' Teeth and Dragons Blood.
They visit the market at the Very End of the Earth, where they choose from the Pool of Lost Socks and buy some Rompadenti biscuits. They camp out in an orange orchard and Jess learns about the Modern Witch's Brewing Pyramid.
Jess brews up a Shock Brew which makes Miss Strega and the familiars itch all night. But Miss Strega gets her own back on Jessica for the itchy brew, by giving her a Rompadenti biscuit with her name on . . . luckily Jess uses the Dragon's Blood to make the writing disappear, otherwise who knows what might have happened.