Gaggles of students chattered between the chairs and sofas of the Gryffindor common room. Flames crackled in the grate and a slow draft of smoke swirled up the chimney. The scent of burning pine hovered across the room.

Almost there. Harry cast a glance ‘round the room and caught Colin Creevey’s eye. He let a faint touch of magic connect their thoughts. Let’s see…

Flashes of a tinsel-decked tree, neatly wrapped presents and a small mountain of sprouts passed through Harry’s mind. Soft, comfortable ease and cheer suffused them like the heat of a long, warm bath. A snatch of the train journey back to the castle flashed through his thoughts, a rattle of rails and the highland heath through cold glass. Excitement churned in his stomach, tinged with faint dread. Pink furnishings surrounded a bubbling envelope of thick, yellow pus. Fear lanced through him, then he found himself back in his bed in a deafening crack.

Harry broke the connection. Dobby saved him… He grimaced at the memory of the dangerous pus. And Umbridge needs to go. She’s already trying to harm students and Dumbledore’s still here. She’s unhinged.

A huge book thumped down beside him. Nev slumped into the chair beside Harry.

'Magical cacti… Looking for something interesting?' Harry asked.

'Assyrian magical plants.' Nev flicked through the pages. 'There's supposed to be very special types of soil that Hannah needs to survive.'

'Still calling it Hannah, then.' Harry laughed. 'Has she found out yet?'

'She's only been back for a few days. Who would’ve told her?'

'Professor Sprout.' Harry grinned. 'She's bound to mention the prized possession of her favourite pupil to the best Herbology student in her house.'

Nev’s face turned red. 'Please stop.’

'That bad?' Harry smirked. 'Look on the bright side, at least now you know she’ll be flattered you've named it after her. Professor Sprout will say nothing but nice things about Hannah, your Hannah, the cactus Hannah, that is.'

‘What will it take for you to stop?’

‘I'll stop, but only when you've asked her to Hogsmeade, otherwise I'll just get worse and worse.'

'That's the most horrible way of making sure I ask her out,' Nev muttered. 'You couldn't have just tried to convince me she would say yes, could you?'

'I didn't think it would be as fun,' Harry quipped. 'Do you know anything about runes, Nev?'

'Nothing that you don't know.' He shrugged. 'I don't even take the subject.'

'So I'll have to wait for Hermione to come down and start enthusing about her essay to figure out what I might’ve missed and can use to fill in the last inch or so.’ He sighed. ‘I don’t miss her lecturing, or her constant condescension, but she was good at essays.’

'I'm not sure she's done it yet.’ Nev lowered his voice. 'I heard Lavender tell Ron Hermione was up all night. Apparently, she’d some kind of nightmare. She definitely wasn't taking anywhere near as many notes as normal today, so she must’ve been tired. Ron's been pretty withdrawn, too, I've only seen him voluntarily speaking to the guys in our dorm, Hermione, and Lavender.'

'Ron's father died just before Christmas.'

'I didn't know.' Nev grimaced. ‘Bloody hell. I didn’t even tell him I was sorry.’

'It's not exactly something to shout about.’ Harry frowned. ‘And telling him you’re sorry wouldn’t help him feel better anyway.’

'No. It doesn’t.’ Nev closed his book. ‘It explains what he said to Romilda Vane, though.'

Harry raised an eyebrow.

'She was asking about your earlier adventures. Romilda's well-known for having a bit of a crush on you. Ron told her that they're only adventures for the people who don't get hurt and walked off.'

'They're not adventures at all. Too many people nearly died. Me, Ginny, Ron, Hermione, me again. Several times. Calling them adventures is naïve and thoughtless.'

But I was playing hero. Saving all the people who’d never risk themselves for me.

Nev returned to flicking through his giant Herbology tome. His frown grew deeper and deeper with each turned page.

'Something wrong?' Harry enquired.

'I'm going to have trouble re-potting Hannah.'

Harry stifled a laugh.

‘Shut up.’ Nev breezed through a few more pages. 'The silica content of the soil has to be just right or it becomes too alkaline and she'll die.'

'Can't you just order some special soil from wherever it's native to?'

'Hannah comes from Assyria. That's cheating, really, though. You're supposed to make your own blend of soil types, but I guess it would be better than letting her die.'

'What would Hannah think if you let her namesake wilt from neglect?' Harry pulled a three centimetre roll of parchment from his pocket and unshrunk it. 'I'm going to go and give this Arithmancy essay to Professor Vector and hope she doesn’t read any of it. It's not due until tomorrow, but I don't want to see it anymore.'

'Fair enough.' Nev chuckled. 'I've got lots of things to research for taking care of Hannah, so I'll still be here for a while.'

I’ll go down and see Salazar, then.

'I might go for a walk down near the lake instead of bothering with Binns,' Harry said. 'Don't wait for me or anything after.'

Nev shrugged, 'I wasn't going to. I've got to run a DA meeting. It’s the first one since everyone's come back.'

'Enjoy.'

And he will. The corner of his lips crooked. It’s good to see him doing better.

He passed Ron and Lavender on his way to Professor Vector’s submissions shelf, catching Ron’s gaze. A soft, constant ache, clouded flashes of sombre Weasley family moments and the glimpse of a slim, silver chain dropping from his fingers into Hermione’s cleavage.

Can’t unsee that. Harry broke the connection and slid his essay onto the shelf. Lavender’s going to be pissed if she finds out, though. That looked like an expensive present.

He threw a glance up and down the corridor, then disillusioned himself and strode up the staircase and along the second floor corridor.

'Hello, Myrtle.' Harry glimpsed a flash of pearl-white through the door of her cubicle. 'How’ve you been?'

'Harry.' She floated over, blushing a deep silver. 'I've been alright, just drifting around. I keep feeling like I’ve forgotten something important, though.'

‘If it’s anything you saw in the Prefect's Bathroom, then I don’t want to know,' Harry quipped.

Myrtle giggled. 'Are you sure?'

Harry laughed. 'If you must…’

'Cedric Diggory was there yesterday for the first time since he came back after Christmas. He had a really long bath.' Myrtle sighed. 'All the bubbles ran out.'

'You're incorrigible.' Harry grinned. 'Didn't he see you?'

'No. I can be sneaky if I want to.'

'Well, no peeking on me if I get made prefect next year.’ He opened the chamber. ‘I want to be able to bathe in peace.’

Myrtle watched the entrance to the chamber appear with a strange gleam in her eye. 'No promises, Harry,’ she murmured.

Cold, dense air closed over him as he descended the steps. Goosebumps prickled along his arms and he shivered as he stepped into the study

'Cold?' Salazar asked.

Harry cast a couple of warming charms on himself. 'It's not warm down here. Why couldn't you have included a fireplace or something?'

'Where would I put a chimney for the smoke?'

'You're Salazar Slytherin.’

Salazar chortled. 'Nobody's turned that line around on me since Godric got himself killed chasing myths.' He stroked the head of his snake. 'Why have you come?'

'To learn, of course,' Harry said. 'And maybe discuss a few ideas with you.'

‘If you want to learn something, it would be best for it to be blood magic,' Salazar said. 'That or you can try and improve your duelling skills.'

'Why not both?' Harry gestured at the time-turner.

The story has been taken without consent; if you see it on Amazon, report the incident.

'As long as you don't overuse it. You were using it far too much last year, but we didn't have much choice to make sure you were skilled enough to survive. Overuse causes severe mental strain.’

'We wouldn't want that,' Harry said. 'Then there'd be two senile people in here.'

'That's why you should only use it sparingly,' Salazar sniped. 'Best to only have one of you at any given time.'

Harry chuckled. 'Blood magic first. I can learn here for a bit, while future me practises wand motions outside.'

Salazar ran his fingers through his goatee. 'Before we start on blood magic, have you got anywhere with the mind arts?'

'I'm capable of utilising passive legilimency now,' Harry said. 'I haven't tried it on more than a handful of unprotected minds to avoid the risk of detection, but I can do it.'

'It shouldn't make too much difference,' Salazar said. 'The connection is so faint and slight it takes a competent practitioner to detect or prevent it.'

'I noticed Dumbledore's.’

'You're naturally gifted at this branch of magic, all our family is, you're more than just competent.'

‘Modest as ever.’

'The truth is the truth,' Salazar said. 'Now, blood magic. Do you remember what I taught you before?'

'You pretty much told me that it used blood as a medium and was often sacrificial,' Harry said.

Salazar folded his arms and sniffed. 'I doubt I said it so inelegantly, but that is a very basic paraphrasing of a rudimentary understanding.'

'I'm happy to listen to a more elegant definition.'

‘Blood magic is any magic that uses blood as a medium or tether, which’s what I told you.' Salazar drummed his fingers on the top of his serpent’s head. ‘Because of its power, it’s usually used in ritualistic, sacrificial magic. However, it can be used for just about anything that magic can be used to do: rituals like you’ve done, warding, enchanting, if you’ve the imagination, you can do it.’

Fleur might find this interesting. A small smile slipped onto his lips. I could do the blood bit and she could make so many clever things.

'You're not listening,' Salazar snapped.

'I was considering the applications to enchanting,' Harry retorted.

'You were thinking about Fleur Delacour again.’ A soft gleam appeared in Salazar’s eyes. ‘You had that silly smile on your face.'

Harry fought down a flush. 'I'm listening.’

'Good.’ Salazar’s eyes darkened. ‘We’ll start with wards. You may need to know about those soon.’

‘Voldemort?’

‘Tom shares our family enthusiasm for such magic. I can’t speak for Voldemort, but I doubt he would abandon the use of powerful magic.’

‘I can’t imagine he would, either.’

‘Obviously, you can use blood magic as a medium in sacrificial magic to create very powerful wards like those on this chamber. Other times, you might not need power so much as specificity. A sacrifice of blood can grant you access to wards, like a key for a lock. You can either choose the ward to only allow through those who sacrificed blood in the ward’s creation, or you can allow anyone to sacrifice some of their blood to gain entry. The latter can be very useful in creating traps. If your enemy thinks that spattering a bit of blood will grant him entry, he might be tempted to risk it. There’re all sorts of nasty surprises in which you can catch an overconfident wizard who’s willingly given blood to you.’

'Can they be broken?'

‘All wards can be broken if you’ve sufficient power.’ He uncoiled his snake from his arm and wound it back ‘round his forearm in a slow, thoughtful manner. ‘However, it’s often the worst way to break a ward, because it forces you into a direct conflict of power. You have to expend at least as much magic as was put into the ward to overcome it. There’s almost always a better way.'

'What about the wards tied to this chamber?' Harry enquired. 'How do they work?'

'More complex. I did both.’ Pride coloured Salazar’s tone. ‘The wards of this chamber are bound to my blood. Only a parselmouth can speak the words to open the entrance and only someone of my bloodline can pass through the other wards. It's why you can apparate in and out of here, but nobody else can.'

'Except Voldemort,' Harry said.

'Except Voldemort.’ Salazar’s gaze turned distant. ‘But I knew Tom well and despite twisting himself into Voldemort, he likely retains much of the same character. He would not come here until it's worth the risk. He never came back after leaving the school, not once.'

'What about portkeys?'

'Only someone of my blood can portkey here through the wards, though anyone who has seen the inside can create a portkey here.'

'What would happen if they tried?' Harry asked.

'I don't know,' Salazar mused. 'Maybe you should get someone to try, just to find out. I suppose the portkey would just fail, or they might bounce off and arrive nearby. They might even vanish completely!’

‘Perhaps another time,' Harry said. ‘I’d like to save playing with experimental magic until I no longer want to live a long and fulfilling life. How did you make the wards?'

‘Sacrifice,’ Salazar whispered. ‘Magic like that requires will and intent that can’t be measured with words, blood, runes, or anything so simple. It takes feeling. It takes pain. It takes determination. You have to know how much it will hurt to accomplish and you have to want it enough to do it anyway.’

‘I don't understand how you bind the magic to your bloodline,’ Harry said. ‘It makes sense that the stronger the magic, the further you must go, but I don’t get how to actually attach the magic to a bloodline.’

'It's abstract magic,' Salazar murmured. ‘I drew a runic description of my intent within the confines of the chamber using my blood as ink just as if it were a simple ritual. That sacrifice of blood allowed me to make my blood both the medium and the key to the piece of magic. You have to put it in the runes and hold it in your mind as you create it.'

Harry turned that over in his head. 'I think I understand. I could probably draw the runes. In fact, I guess I could draw them all wrong as long as I didn’t realise.'

‘Very true,’ Salazar said. ‘But it’s best not to try that, something weird might happen if you noticed halfway through you’d done it wrong.’

‘I’d just need something to sacrifice.'

‘You’ve sacrificed much already,’ Salazar murmured. ‘Everything you’ve given up to survive, all those things you’ve left behind to reach that lovely French sunset, they’ll be with you in every piece of magic you cast.’

‘Is that why Voldemort’s so powerful?’ Harry wondered. ‘Has he sacrificed so much his intent is just that strong?’

A small smile curved Salazar’s lips. ‘I fear so. And, in a way, I’m still a little proud of the magic Tom has managed, but there are some things you shouldn’t sacrifice, Harry. There comes a point when you’ve cut away so much of yourself that there’s very little left.’

There’s only power. The chalk-white face and red eyes protruding from the back of Quirrell’s skull floated through Harry’s mind. Did Tom sacrifice everything else? Bloody hell.

'I see.’ He buried thoughts of Tom and all the little, dear things that must’ve been left in the wake of his path to becoming Voldemort. 'So if I wanted to create blood wards around a house to protect someone important to me, I’d have to sacrifice something of approximately equal value.'

'Yes,' Salazar said. 'Though it would be strengthened by everything you’ve already sacrificed and you can only make wards so strong before sacrificing more makes no difference.'

Harry nodded. 'Makes sense. How would I enchant something using blood magic?'

'That's the simplest use.' Salazar flapped a hand at him. 'Lots of wizards and witches did this to ensure only their bloodline could use their creations and, of course, blood’s a powerful medium to use for the creation of the object itself.’ Deep creases wrinkled Salazar’s brow. ‘Beyond that, I would wager a great deal that most of the legendary, magical artefacts were made using sacrificial magic of the greatest sort and blood as a medium.'

'A powerful sacrifice and a powerful medium to create the strongest possible enchantment,' Harry said.

‘More than that.' Salazar released a long sigh. ‘I never got my hands on one, despite searching for a very long time. They’re few and far between, jealously guarded, too. Imagine, though, Harry, the sort of artefact you could create from the shared sacrifice and intent of a hundred wizards.’

If a single wizard can create something like this chamber, then something created by a hundred would be unbelievably powerful. A small shiver rippled down Harry’s spine. No wonder they’re few and far between.

‘I don’t know of any, really,’ he said.

'The Caduceus was one,' Salazar said. 'I searched for it as my wife’s health failed. It was created back before even the Classical Era, but was lost during the fall of Rome. It was reputed to be a staff of healing without comparison. An item so powerful that any magic cast through it with the intention to heal was almost always successful. Rumours were that it could even prevent death. It was so famous it remains well known even amongst muggles.'

'Any others?' Harry asked.

'A few.' Salazar cracked a grin. 'I'll tell you about some of them in the future, but you have more important things to worry about now.'

'That's true.' Harry nodded. ‘Fudge, the current Minister, will jump at any chance to get rid of Dumbledore and earn some credibility back. His days are numbered, so Dumbledore will likely be back by next year, if he wants to be.'

'If his martyr is here, he will want to be,' Salazar muttered.

Harry scowled and swallowed a shard of cold rage. 'No doubt.’

‘Do you have a plan?’

'Dumbledore gets ousted. Umbridge gets dealt with. Sirius gets me into the Ministry. I get the prophecy, hear it, then destroy it.’ Harry bounced his fingertips together. ‘My cloak ought to get me through any wards at the Ministry.’

'Yes.' Salazar’s gaze sharpened. 'Don't lose that cloak, Harry. If it truly makes your magic completely undetectable, then you have something on par with the Caduceus in your possession.'

Harry’s eyes snapped to the pool of silken material upon Salazar’s desk. 'Really?'

'Oh yes. It's not a story for now, you have enough on your mind for the moment, but in the near future it might be prudent for you to learn a little more about that cloak.’ A small, rueful smile curved his lips. 'You should always know exactly how much something means to you.'

'It's the only thing I have from my father,' Harry said. 'But I’m less attached to it than I used to be. I’ve grown used to not having much family.'

'Well, I'm not advocating sacrificing it for any reason. In fact, I advise against it other than to save your own life. It's likely very valuable.'

'How valuable?'

'Priceless,' Salazar whispered. 'It's the sort of thing wizards spend lifetimes looking for.'

'How intriguing,' Harry murmured.

'Just don't lose it,' Salazar snapped. ‘If you do, I will find a way to claw myself free of this canvas and beat you to death with the pieces of my former frame.’

Harry snorted. ‘I did wonder how good it was. Dumbledore did find me under it once, but I’m not sure if he could actually detect me, or if he just deduced it indirectly.’

‘Indirectly, I suspect,’ Salazar said. ‘Death is not so easily outdone.’

‘What?'

‘Something for another time. You have enough to do without getting obsessed with old myths like Godric and I.’

That’s true enough.

Harry reached for the time-turner, ducking his head through the thin gold chain. 'Any suggestions for what I should practice for my duelling?'

'Try casting your shield charm and your silly butterflies simultaneously. If you can manage that then you'll have a very powerful defence to fall back upon should you need to weather the storm for a bit.'

'How can I cast two pieces of magic at the same time without weakening one or both?' Harry demanded. ‘They have different intentions.’

‘Not different intentions, different mechanics,’ Salazar said. ‘You’re looking too closely at how the spells work. Forget that one is conjuring butterflies and another a shield. The broad intent behind them is the same, so once you’re able to cast without incantation or wand motion, you can produce them simultaneously.’

'How is it any better than deflecting hexes from within the butterflies?'

'It's safer,' Salazar said. 'You won't be able to attack and it's less flexible than duelling while your animated defence protects you, but defensively it’s stronger.'

'I'll practise it.' Harry flipped the time-turner several times and strode out over the bridge. ‘I’m getting the hang of bringing it all together.’

'Practise chaining your wand motions too,' Salazar called.

Harry shot him a thumbs up over his shoulder as the room blurred and time flowed backward around him.