On the third day of Christmas, dear Rowling gave to we/Some stuff about potions and cauldrons.

Okay, so maybe that doesn’t rhyme. But today’s Pottermore riddle does:

His potions lessons are full of interesting things

With students keen to see what each day will bring

With his large moustache and rotund shape

Who teaches this class after Professor Snape?

The answer: Professor Slughorn—and note that you’ve got to type it exactly like that (not “Slughorn,” not “Horace Slughorn”) to find today’s new J.K. Rowling writing. Appropriately enough, it focuses on the magical world of potions, answering one age-old question—can a Muggle create a magic potion, if she uses the right ingredients?—revealing that Snape teaches Potions because Rowling herself hated chemistry in school, and noting that the author once considered making Helga Hufflepuff’s Hallow a cauldron, “but there was something slightly comical and incongruous about having such a large and heavy Horcrux.”

Head to Pottermore for more… Potter.