As the trio head towards Transfiguration, Harry resolves to ask [=McGonagall=] if he can visit Hogsmeade this weekend despite not having a signed permission form. Before class begins however, we get a nice bit of drama: Lavender Brown's just found out that Binky - her pet rabbit - has been killed by a fox, and to make things interesting, she claims that it's in accordance with one of the predictions Trelawney made in Divination: the event Lavender dreaded the most would happen on this date.
Hermione, ever the Divination skeptic, decides to argue that this is bull: Lavender couldn't have been dreading her rabbit's death, since he was only a baby when it happened, and it's come as a complete shock. Also, while Lavender did hear about it this morning, there's no evidence that Binky was killed ''today''. Did it ever occur to you that [[TooSoon this might not be a good time]] for this particular discussion, Hermione?
Thankfully, [=McGonagall=] chooses this moment to start class, warding off a potential flare-up between Hermione and Ron. And at the end of the lesson, Harry asks [=McGonagall=] about visiting Hogsmeade, even going so far as to ask her to sign his form. It doesn't go well: [=McGonagall=], while not unkind to him, insists that since he didn't have a parent or guardian sign his form, he's not visiting Hogsmeade this weekend. So while every other third year gets to visit places like the Three Broomsticks, Honeydukes Sweet Shop, Zonko's Joke Shop and The Shrieking Shack, poor Harry's going to be stuck in the castle for the weekend.
It's not all bad though: Lupin decides to invite Harry for tea in his office, and Harry takes the opportunity to ask him why he stopped the Boggart from attacking Harry in that last Defense Against the Dart Arts lesson. Lupin explains that he had assumed Harry's worst fear would be Voldemort, and he thought it best that the BigBad of the series didn't materialise in the staffroom. Harry admits that he had thought of Voldemort at first, but then he felt the Dementors were more scary. Lupin takes this to mean that Harry fears fear itself.
Seconds later, Snape decides to pop in. He isn't staying long however, just dropping off some kind of potion for Lupin that, for whatever reason, is emitting smoke. Lupin explains to Harry that the potion is the only working medicine for an illness he currently has, but Harry isn't convinced. Remembering that Snape has been trying to get the Defense Against the Dart Arts teacher's job for years, Harry tries and fails to warn Lupin that Snape may have given him poison. For the time being though, the only problem with the potion is that it tastes like crap.
As the Gryffindors - those who just returned from Hogsmeade and those who stayed at the castle - return to the common room after the Halloween feast that same day, they discover that getting inside's going to be a problem; the Fat Lady's portrait has been slashed up with a knife, and the woman herself is nowhere to be seen. Dumbledore is summoned, and he tells Percy to tell Filch to find the Fat Lady, but luckily for Percy and Filch, they're saved the trouble when Peeves - who happened to see the Fat Lady running - pops by.
The poltergeist then ends the chapter with a bombshell: The Fat Lady was attacked when she refused to let someone into the common room, and that someone? [[WhamLine None other than Sirius Black]].