"Well, you know the Whomping Willow. It -- it doesn't like being hit."
-- Ron Weasley regarding Harry's Nimbus 2000
The students are gathered in the Great Hall for the night, Quidditch practice continues, DADA is taken over by Snape when Lupin falls ill, Peeves wakes Harry, Quidditch match between Gryffindor and Hufflepuff in a thunderstorm, Harry sees the Grim and Dementors on the pitch and passes out to awaken in hospital having lost the game.
Calendar and Dates
Still to come.
Interesting facts and notes
The chapter title is a nice play on words, referring both to the fact that the defeat was grim and that it was marked by the presence of a (supposed) Grim.
Exceptional character moments
All the students spending the night in the Great Hall and sleeping in purple sleeping bags because of the reports of seeing Sirius Black inside Hogwarts castle.
A portrait of Sir Cadogan temporarily replacing the portrait of the Fat Lady.
Harry telling Professor McGonagall that he knows that Sirius Black is coming after him.
The Gryffindor and Slytherin Quidditch match changing to Gryffindor versus Hufflepuff due to Malfory's injured arm.
Due to an illness Professor Snape teaching Professor Lupin's class and assigning the students a two rolls of parchment assignment on ways to recognize and kill werewolves.
Snape giving Ron a detention of scrubbing the bedpans in the hospital wing without magic.
The Gryffindor/Hufflepuff Quidditch match played during a severe, cold rainstorm.
During a time-out of the Quidditch match, Hermione putting the Impervius spell on Harry's glasses causing them to repel rain.
Harry suddenly seeing an enormous shaggy black dog imprinted against the sky in the topmost empty rows of seats during the Quidditch match.
After seeing at least a hundred dementors Harry, hearing voices in his head, falling off his broom and hitting the ground.
Waking in the hospital wing, Harry discovering that he had lost his first Quidditch match.
Harry learning that after he fell off his Nimbus 2000, it flew into the Whomping Willow and was destroyed.
"It seems - almost impossible - that Black could have entered the school without inside help. I did express my concerns when you appointed --" Professor Snape to Professor Dumbledore
"I do not believe a single person inside this castle would have helped Black enter it." Professor Dumbledore
"...I'm afraid no dementor will cross the threshold of this castle while I am headmaster." Professor Dumbledore
"I know he's after me. I heard Ron's dad telling his mum." Harry to Professor McGonagall regarding Sirius Black
"He's that tall, good-looking one isn't he." Angelina Johnson referring to Cedric Diggory
"Oliver, calm down! We're taking Hufflepuff very seriously. Seriously. Fred Weasley
"Why couldn't Black have hidden in Snape's office, eh? He could have finished him off for us!" Ron
"You know, I reckon Ron was right about you. Leave Scabbers alone." Harry to Crookshanks
"Well, you know the Whomping Willow. It -- it doesn't like being hit." Ron regarding Harry's Nimbus 2000