Chapter 6 - "Glideroy Lockhart" - In which Ron receives a Howler, they learn about mandrakes in Herbology, Colin Creevey asks for an autographed photo, Lockhart is the new Defence Against the Dark Arts teacher, and they learn about Cornish pixies.
Harry and Ron's Glorious Start to their Second Year
Stuck in Snape's office, Harry and Ron are forced to try to explain their actions, first by Snape and then by McGonagall and [Dumbledore]. They are admonished, given detentions, and warned that farther misbehavior will warrant expulsion from Hogwarts. McGonagall then leaves them to eat dinner there before heading up to Gryffindor Tower.
Start of Classes