Book 6 | Ch:18 - Birthday Surprises

SPOILERS:

Harry gives Slughorn a bezoar instead of an antidote in Potions class, then asks him unsuccessfully about Horcruxes. The sixth-years then have their first apparition lesson, where Harry overhears Malfoy saying Crabbe has been acting as his lookout, and Harry starts watching the Marauder’s Map. Then, on Ron’s birthday, Ron accidentally consumes Romilda Vane’s love potion and Harry takes him to Slughorn to get an antidote; there, Slughorn gives Ron some poisoned mead and Harry saves his life with a bezoar.