"Harry Potter has to go into the lake and find his Wheezy - "
HRH discuss the situation in Charms class, HRH search for spells to help with the second task, and Hagrid returns to Care of Magical Creatures. Harry continues his studying all through the night before the second task, to be awakened by Dobby (who gives him gillyweed for breathing underwater). Harry performs the second task: to recover from the merpeople what was taken from each Champion. Harry rescues Ron and Fleur’s sister, tying with Cedric on points.
Calendar and Dates
This chapter begins the morning after Harry's visit to the prefects' bathroom, and ends just after the Second Task on the 24th of February.
Interesting facts and notes
This chapter echoes the pattern of the first task: frantic preparation at the last minute, and the unexpected attendance of one of the three elder Weasley brothers.
"You said you'd already worked out that egg clue!" said Hermione indignantly.
From the tone of Hermione's remark, it is clear that Harry has just told her and Ron what he learned from the golden egg. This suggests that the conversation is taking place at Harry's first opportunity to talk with his friends in private that day, which in turn strongly suggests that Charms class takes place before lunch, at least on this particular day of the week.
He, Ron, and Hermione were sitting at the very back of the Charms class with a table to themselves.
Since this conversation is taking place on a Friday (see below), this tells us that Harry's fourth-year Charms class meets on Fridays.
Neville's aim was so poor that he kept accidentally sending much heavier things flying across the room - Professor Flitwick, for instance.
Neville's aim is not necessarily due to poor hand/eye coordination. Harry and Ron similarly display bad aim at various points during the lesson, and they have good hand/eye coordination (or they'd never be able to play Quidditch properly). Neville's difficulties, like those of Harry and Ron, may be due to difficulty in concentrating properly.
Neville's difficulties with the Banishing Charm are interesting, because instead of (for instance) having no effect, we are told that his problem is that he is accidentally moving much heavier objects than what he is supposed to be aiming at. This may be an indication that Neville has strong magical ability that just isn't being properly controlled.
...as Professor Flitwick went whizzing resignedly past them, landing on top of a large cabinet.
Apart from telling us that the furnishings of the Charms classroom include a large cabinet as well as the tables at which the students are working, this shows us how patient Flitwick is with his students.
Harry had been recounting his adventures of the previous night in whispered installments for the last half hour.
Consequently, this scene is taking place on the day after Harry's visit to the prefects' bathroom. Since that was on a Thursday, this scene is on a Friday. Furthermore, the length of Harry's explanation suggests that Charms class on Fridays is at least an hour long.
"If only we'd done human Transfiguration already! But I don't think we start that until sixth year, and it can go badly wrong if you don't know what you're doing..."
This tells us a little about the expected sixth-year Transfiguration curriculum. Hermione's remarks on the danger of such Transfiguration expand upon what we have already been told about one of the reasons the Ministry keeps tabs on people who can perform an Animagus Transfiguration.
...two unicorn foals. Unlike full-grown unicorns, they were pure gold. Parvati and Lavender went into transports of delight at the sight of them, and even Pansy Parkinson had to work hard to conceal how much she liked them.
So Pansy isn't all bad.
"Easier ter spot than the adults," Hagrid told the class. "They turn silver when they're abou' two years old, an' they grow horns at aroun' four."
We don't know whether unicorns periodically shed and regrow their horns, as deer do, or whether they're velveted when first grown.
"Don' go pure white 'til they're full-grown, round about seven. They're a bit more trustin' when they're babies...don' mind boys so much...c'mon, move in a bit, yeh can pat 'em if yeh want...give 'em a few o'these sugar lumps..."
So unicorns take a couple of years longer to reach maturity than horses do, but like horses they enjoy the occasional lump of sugar.
'Take two pints of water, half a pound of shredded mandrake leaves and a newt...'
This tells us that newts are Potion ingredients.
"It takes years to become an Animagus, and then you have to register yourself and everything," said Hermione vaguely, now squinting down the index of Weird Wizarding Dilemmas and Their Solutions. "Professor McGonagall told us, remember...you've got to register yourself with the Improper Use of Magic Office...what animal you become, and your markings, so you can't abuse it..."
This is one of the earliest indications that the Improper Use of Magic Office has a function other than monitoring under-age magic; they maintain the Animagus registry.
...snapping Weird Wizarding Dilemmas shut. "Who on earth wants to make their nose hair grow into ringlets?"
This tells us a little about the contents of the book, although not why that particular situation is either a weird wizarding dilemma or its solution.
By eight o'clock, Madam Pince had extinguished all the lamps and came to chivvy Harry out of the library.
So the Hogwarts library closes at eight o'clock in the evening, and apparently teachers do not commonly grant notes of permission to stay late (or Harry - and certainly Hermione - would have asked before now).
Wand tip alight, he crept along the bookshelves, pulling down more books -
We know that none of the spellbooks in this chapter appears to mention the Bubble-Head Charm - at least, not in any context that suggests using it underwater.
...books of hexes and charms, books on merpeople and water monsters, books on famous witches and wizards, on magical inventions, on anything at all that might include one passing reference to underwater survival.
Interesting. The discoverer of gillyweed is on a famous wizard card, so Harry just had bad luck in not finding out about gillyweed this way.
Four people were bound tightly to the tail of the stone merperson.
Ron was tied between Hermione and Cho Chang. There was also a girl who looked no older than eight, whose clouds of silvery hair made Harry feel sure that she was Fleur Delacour's sister. All four of them appeared to be in a very deep sleep. Their heads were lolling onto their shoulders, and fine streams of bubbles kept issuing from their mouths.
Exceptional character moments
Harry, for whom Ron is the thing he'd miss the most. (At least in the opinion of the Triwizard judges.)