—THE NEXT FEW DAYS PASSED BY WITHOUT ANY GREAT INCIDENTS, UNLESS YOU COUNTED NEVILLE LONGBOTTOM MELTING HIS SIXTH CAULDRON IN POTIONS. Professor Snape, who seemed to have attained new levels of vindictiveness over the summer, gave Longbottom detention, and Longbottom returned from it in a state of nervous collapse, having been made to disembowel a barrelful of horned toads.

"You know why Snape's in such a foul mood, don't you?" asked Rigel curiously to Draco as they watched Granger teaching Longbottom a Scouring Charm to remove the toad guts from under his fingernails.

"Yeah," said Draco. "Moody."

It was common knowledge that Snape really wanted the Dark Arts job, and he had now failed to get it for the fourth year running.

Snape had disliked all of their previous Dark Arts teachers, and shown it – but he seemed strangely wary of displaying overt animosity to Mad-Eye Moody.

Indeed, whenever Rigel saw the two of them together – at mealtimes, or when they passed in the corridors – he had the distinct impression that Snape was avoiding Moody's eye, whether magical or normal.

"I reckon Snape's a bit scared of him, you know," Blaise said thoughtfully.

••

The Gryffindor and Slytherin fourth-years were looking forward to Moody's first lesson so much that they arrived early after lunch on Thursday and queued up outside his classroom before the bell had even rung.

The only person missing was Rigel, who turned up just in time for the lesson and was the only person not excited. In fact, he looked bored.

"C'mon, quick, or we won't get decent seats." Draco whispered.

They hurried into three chairs right in front of the teacher's desk, took out their copies of The Dark Forces: A Guide to Self-Protection, and waited, the Gryffindors unusually quiet, but it was normal to see the Slytherins quiet.

Soon they heard Moody's distinctive clunking footsteps coming down the corridor, and he entered the room, looking as strange and frightening as ever. They could just see his clawed, wooden foot protruding from underneath his robes.

"You can put those away," he growled, stumping over to his desk and sitting down, "those books. You won't need them."

They returned the books to their bags, the Gryffindors looking excited.

Moody took out a register, shook his long mane of grizzled grey hair out of his twisted and scarred face and began to call out names, his normal eye moving steadily down the list while his magical eye swivelled around, fixing upon each student as he or she answered.

"Right then," he started, when the last person had declared themselves present, "I've had a letter from Professor Black about this class. Seems you've had a pretty thorough grounding in tackling Dark creatures – you've covered Boggarts, Red Caps, Hinkypunks, Grindylows, Kappas and werewolves, is that right?"

There was a general murmur of assent.

"But you're behind—very behind—on dealing with curses," said Moody. "So I'm here to bring you up to scratch on what wizards can do to each other. I've got one year to teach you how to deal with Dark—"

"What, aren't you staying?" Ron Weasley blurted out.

Moody's magical eye spun around to stare at Weasley; Weasley looked extremely apprehensive, but after a moment Moody smiled – the first time Rigel had seen him do so.

The effect was to make his heavily scarred face look more twisted and contorted than ever, but it was nevertheless a relief to know that he ever did anything as friendly as smile.

Ron looked deeply relieved.

"You'll be Arthur Weasley's son, eh?" Moody asked. "Your father got me out of a very tight corner a few days ago... yeah, I'm staying just the one year. Special favour to Dumbledore... one year, and then back to my quiet retirement."

He gave a harsh laugh, and then clapped his gnarled hands together.

"So – straight into it. Curses. They come in many strengths and forms. Now, according to the Ministry of Magic, I'm supposed to teach you counter-curses and leave it at that. I'm not supposed to show you what illegal Dark curses look like until you're in the sixth year. You're not supposed to be old enough to deal with it 'til then..

But Professor Dumbledore's got a higher opinion of your nerves, he reckons you can cope, and I say, the sooner you know what you're up against, the better. How are you supposed to defend yourself against something you've never seen? A wizard who's about to put an illegal curse on you isn't going to tell you what he's about to do.

He's not going to do it nice and polite to your face. You need to be prepared. You need to be alert and watchful. You need to put that away, Miss Brown, when I'm talking."

Lavender Brown jumped and blushed. She had been showing Parvati her completed horoscope under the desk.

Apparently Moody's magical eye could see through solid wood, as well as out of the back of his head.

"So... do any of you know which curses are most heavily punished by wizarding law?"

Several hands rose tentatively into the air, including Weasley's.

Moody pointed at Weasley, though his magical eye was still fixed on Lavender.

"Er," said Weasley tentatively, "my dad told me about one... is it called the Imperius curse, or something?"

"Ah, yes," said Moody appreciatively. "Your father would know that one. Gave the Ministry a lot of trouble at one time, the Imperius curse."

Moody got heavily to his mismatched feet, opened his desk drawer, and took out a glass jar.

Three large, black spiders were scuttling around inside it.

Moody reached into the jar, caught one of the spiders and held it in the palm of his hand so that they could all see it.

He then pointed his wand at it, and muttered, "Imperio!"

The spider leapt from Moody's hand on a fine thread of silk, and began to swing backwards and forwards as though on a trapeze.

It stretched out its legs rigidly, then did a backflip, breaking the thread and landing on the desk, where it began to cartwheel in circles.

Moody jerked his wand, and the spider rose onto two of its hind legs and went into what was unmistakeably a tap dance.

Everyone was laughing – everyone except Moody and Rigel.

"Think it's funny, do you?" Moody growled. "You'd like it, would you, if I did it to you?"

The laughter died away almost instantly. Rigel remembered who the guy actually was— Barty Crouch Jr.— and he was under the imperius curse by his father for years.

"Total control," said Moody quietly, as the spider balled itself up and began to roll over and over. "I could make it jump out of the window, drown itself, throw itself down one of your throats..."

A few students gave an involuntary shudder.

"Years back, there were a lot of witches and wizards being controlled by the Imperius curse," said Moody.

"What is this git playing at?" Draco whispered, not caring about the fact that he would most likely be heard.

"Forget it, Draco." Blaise said, putting a comforting hand on his knee.

"Some job for the Ministry, trying to sort out who was being forced to act, and who was acting of their own free will. The Imperius curse can be fought, and I'll be teaching you how, but it takes real strength of character, and not everyone's got it. Better avoid being hit with it if you can. CONSTANT VIGILANCE!" The Professor barked, and everyone jumped.

Moody picked up the somersaulting spider and threw it back into the jar. "Anyone else know one? Another illegal curse?"

Granger's hand flew into the air and so, to everyone's slight surprise, did Longbottom's. The only class in which Neville Longbottom usually volunteered information was Herbology, which was easily his best subject.

Longbottom looked surprised at his own daring.

"Yes?" asked Moody, his magical eye rolling right over to fix on Neville.

"There's one— the Cruciatus curse," said Longbottom, in a small but distinct voice.

Moody was looking very intently at Neville, this time with both eyes.

"Your name's Longbottom?" he said, his magical eye swooping down to check the register again.

He nodded nervously, but Moody made no further enquiries.

Turning back to the class at large, he reached into the jar for the next spider and placed it upon the desktop, where it remained motionless, apparently too scared to move.

"The Cruciatus curse," said Moody. "Needs to be a bit bigger for you to get the idea," he said, pointing his wand at the spider. "Engorgio!"

The spider swelled. It was now larger than a tarantula.

Moody raised his wand again, pointed it at the spider, and muttered: "Crucio!"

At once, the spider's legs bent in upon its body;
it rolled over and began to twitch horribly, rocking from side to side.

No sound came from it, but Rigel was sure that if it could have given voice, it would have been screaming.

Moody did not remove his wand, and the spider started to shudder and jerk more violently—

"Stop it!" Granger said shrilly.

Everyone looked at her. She was looking, not at the spider, but at Longbottom, and Rigel, following her gaze, saw that Longbottom's hands were clenched upon the desk in front of him, his knuckles white, his eyes wide and horrified.

Moody raised his wand.

The spider's legs relaxed, but it continued to twitch.

"Reducio,"  Moody muttered, and the spider shrank back to its proper size. He put it back into the jar.

"Pain," said Moody softly. "You don't need thumbscrews or knives to torture someone if you can perform the Cruciatus curse... that one was very popular once, too. Right... anyone know any others?"

Rigel looked around.

From the looks on everyone's faces, he guessed they were all wondering what was going to happen to the last spider.

Granger's hand shook slightly as she raised it into the air.

"Yes?" said Moody, looking at her.

"Avada Kedavra," Granger whispered.

Several people looked uneasily around at her, including Ron Weasley.

"Ah," said Moody, another slight smile twisting his lop-sided mouth. "Yes, the last and worst. Avada Kedavra... the killing curse."

He put his hand into the glass jar, and almost as though it knew what was coming, the third spider scuttled frantically around the bottom of the jar, trying to evade Moody's fingers, but he trapped it, and placed it upon the desktop.

It started to scuttle frantically across the wooden surface.

Moody raised his wand, and Rigel felt a sudden thrill of foreboding.

"Avada Kedavra!" Moody roared.

There was a flash of blinding green light and a rushing sound, as though a vast, invisible something was soaring through the air— instantaneously the spider rolled over onto its back, unmarked, but unmistakably dead.

Several of the girls stifled cries; Draco and Blaise had thrown themselves backwards and almost toppled off their seats.

Moody swept the dead spider off the desk onto the floor. "Not nice," he said calmly. "Not pleasant. And there's no counter-curse. There's no blocking it. Only one known person has ever survived it, and he's sitting right in front of me."

Rigel and Moody made eye contact.

Rigel could feel everyone else looking around at him, too. He looked away and stared at the blank blackboard as though fascinated by it, but not really seeing it at all...

So that was how his parents had died... exactly like that spider. Had they been unblemished and unmarked, too? Had they simply seen the flash of green light and heard the rush of speeding death, before life was wiped from their bodies?

Rigel had been picturing his parents' deaths over and over again for years now, ever since he had been old enough to found out they had been murdered, ever since he'd found out what had happened that night: how Wormtail had betrayed his parents' whereabouts to Voldemort, who had come to find them at their cottage.

How Voldemort had killed Rigel's biological father first. How James Potter had tried to hold him off, while he shouted at his wife to take 'Harry' and run... and Voldemort had advanced on Lily Potter, told her to move aside so that he could kill 'Harry' ... how she had begged him to kill her instead, refused to stop shielding her son... and so Voldemort had murdered her, too, before turning his wand on him...

Rigel knew these details because he had heard his parents' voices when he had fought the Dementors last year – for that was the terrible power of the Dementors: to force their victim to relive the worst memories of their life, and drown, powerless, in their own despair...

Moody was speaking again, from a great distance, it seemed to Rigel.

With a massive effort, he pulled himself back to the present, and listened to what Moody was saying.

"Avada Kedavra's a curse that needs a powerful bit of magic behind it— you could all get your wands out now and point them at me and say the words, and I doubt I'd get so much as a nose-bleed. But that doesn't matter. I'm not here to teach you how to do it.

Now, if there's no counter-curse, why am I showing you? Because you've got to know. You've got to appreciate what the worst is. You don't want to find yourself in a situation where you're facing it. CONSTANT VIGILANCE!" Moody roared, and the whole class jumped again.

"No... those three curses— Avada Kedavra, Imperius and Cruciatus— are known as the Unforgivable Curses. The use of any one of them on a fellow human being is enough to earn a life sentence in Azkaban. That's what you're up against. That's what I've got to teach you to fight. You need preparing. You need arming. But most of all, you need to practise constant, never-ceasing vigilance. Get out your quills... copy this down..."

They spent the rest of the lesson taking notes on each of the Unforgivable Curses, albeit for Rigel— reluctantly.

••

No one spoke until the bell rang—but when Moody had dismissed them and they had left the classroom, a torrent of talk burst forth.

Most people were discussing the curses in awed voices— "Did you see it twitch?"— "and when he killed it – just like that!"

They were talking about the lesson, Rigel thought, as though it had been some sort of spectacular show, but he hadn't found it very entertaining – and nor, it seemed, had Draco, who kept glancing at Rigel every now and then to make sure he was alright.

An odd clunking noise sounded behind them, and they turned to see Professor Moody limping towards them. The three stayed silent, watching him apprehensively, but when he spoke, it was in a much lower and gentler growl than they had yet heard.

Moody turned his magical eye upon Rigel. "You all right, are you, Potter-Black?"

"Black, Professor." Rigel corrected, a hint of a threatening note in his voice, making Moody understand what he was hinting at.

Moody's blue eye quivered slightly in its socket as it surveyed Rigel. Then he said, "You've got to know. It seems harsh, maybe, but you've got to know. No point pretending... well... you might want to leave for lunch."

Rigel stayed quiet, while Blaise started talking. "Some lesson, though, eh?" asked Blaise as they set off for the Great Hall. "They were right, weren't they? He really knows his stuff, Moody, doesn't he? When he did Avada Kedavra, the way that spider just died, just snuffed it right—"

But Blaise fell suddenly silent at the look on Rigel's face, and didn't speak again, other than apologizing a few times.