Come dark lords or heartbreak, classes would go on. But two hours of sleep did not prepare Daphne for four hours of arithmancy the very next day – even pepper-up had its limits. She was very much looking forward to spending her afternoon free period doing absolutely nothing at all, but Professor Sprout had other plans for her two research assistants: the Headmaster had approved "quite an extraordinary acquisition", which had finally arrived after a lengthy voyage.

Trekking down half-dead to the greenhouses, Daphne immediately recognised the brassy crate: it was coated in goblin-mined orichalcum, which rendered its contents magically inert. Similar receptacles were typically used for transporting particularly sensitive accoutrements like portkeys and were, as Lord Greengrass was often too eager to mention, frightfully expensive.

Longbottom evidently shared her enthusiasm: he volunteered to unpack the large crate, which entailed struggling with a heavy crowbar, since the orichalcum patina repelled nearly all magic. Daphne found herself in the odd position of being honour-bound to not assist: while it certainly did not amuse her to see Longbottom bumble about and drop the crowbar on his toes, manual work was patently unladylike and it would be indecorous to partake.

Finally the crate came apart. Within was a strange plant, unlike any Daphne had ever seen. It was stout, about a metre across but barely knee-height. It resembled a sort of cross between a banana tree and some type of fern, with large, waxy leaves sprouting around a short and heavy trunk. Daphne guessed that it was tropical, which unfortunately put it far beyond the ambit of her knowledge. The House of Greengrass was the foremost magriculturalist in Europe, but had no expertise in importing from farther afield. Perhaps that was something to consider for the far future.

Longbottom wiped the sweat of his brow, finished the tea that Professor Sprout had offered him, and asked, "is that a Peruvian giant nirnroot?" That sounded only vaguely familiar to Daphne, which made her abashed.

"Quite right, Mr. Longbottom. And I take it you know all about its properties," said the Professor.

"I read that it absorbs magic. It's the only plant that does, and nobody knows how it works."

"It's the only known plant that does. Remember, herbology is an unending task. I doubt we can ever truly catalogue every plant that exists, even if we each lived as long as the Flamels. But the Peruvian giant nirnroot is indeed an extraordinary plant. As you say, it absorbs magic from its surroundings, which allows it to grow truly enormous with time. Older specimens are also almost impervious to damage. This one is rather young, so do be careful."

"Is that why I'm getting a mild headache, Professor?" asked Daphne.

"Indeed, Miss Greengrass. Our nirnroot has been in a magical vacuum for some months, and is likely thirsting for energy. I'd suggest putting your wands away for now. This is the first live specimen in Britain, and it was decided that it would be planted at Hogwarts so that we can all study it without becoming indisposed. The ambient energy given off by hundreds of witches and wizards should make it quite… sated."

"You mean it can absorb magic from that far away? We're not even in the castle," said Neville.

"I suppose the only way to truly find out is with time," said Professor Sprout. "Though I suspect all should be fine. It's not only the castle itself, but the whole grounds that is awash with magical energy. Besides, the largest nirnroots are known to create magically-inert basins stretching miles in the Amazon, which is why the indigenous Amazonians hold it to be quite sacred. Some even say that they come from another world altogether. While that is almost certainly not true, the nirnroot is indeed a strange plant, of which little is known. Which is exactly what we are trying to remedy."

Daphne's head was now throbbing, and she seemed to hear a faint chiming sound emanating from the nirnroot. Fortunately she was not the only one, and even Professor Sprout was absently rubbing her temples.

"Before we all get migraines, I suggest we start by transplanting it in the field behind the tropical greenhouse, where we will study it in the coming months. Don't worry about watering it; it feeds entirely off magical energies. Mr Longbottom, can you manage?"

Daphne had no desire to be near the nirnroot for a moment longer than necessary, so she rolled up her sleeves and supported one side of its trunk while Longbottom carried the other. He muttered something that might have been surprise or gratitude. Daphne didn't care – she was raised to be sophisticated, not witless. After a great effort, the nirnroot was lifted into a hole that Professor Sprout had already dug, and together they reburied the soil with trowels. Even the small mound of soil took several minutes to move; Daphne thought back to her family's vast acreages and silently wondered how muggles ploughed fields by hand.

By the time Professor Sprout dismissed them, the aching in her heart since yesterday had been entirely drowned out by the throbbing of her skull. Fate was a cruel mistress, and not without a sick sense of humour of which Lord Slytherin would no doubt approve. She craved both food and sleep, but the latter proved the greater need, so Daphne stumbled back to the dungeons to the girls' dormitory. She collapsed on her bed without even changing out of her soiled robes.

After three hours, Daphne was roused by Bertie pawing her face. She cursed herself for missing dinner, and briefly charmed her eyebags for presentability before trudging down to the Great Hall to begin her patrol. Daphne had grown to be quite fond of her partner, but by Morgana, that was not enough to make her wish she would much rather be elsewhere.

"Hello, Granger. Thanks for letting Potter know. We had a good conversation."

"Yes, Harry told me. He wasn't sure at first, you know, but I insisted that he go. And I think he's secretly glad that he did."

"If only boys more often do as they're told."

Granger blushed a little, but said nothing in reply. By unspoken assent, they began their patrol at the quidditch pitch, just like the previous week. Suddenly Granger stopped mid-stride, and turned to Daphne. "I know it's none of my business, but you look terrible. Is everything alright?"

And Daphne could not help but throw her head back and laugh: an unrecognisable chortling sound, so uncouth that she could scarce believe that she was its source. No, nothing is alright. The Heir of Slytherin has returned from beyond the Veil to demand that I seduce Harry Potter. Said Potter then saves me from Draco-bloody-Malfoy who did something to me, that Magic be damned I cannot remember. And I think I like him – a lot. Not Draco, of course. Harry. And Sprout has made me tend to a stupid headache-causing magic-sucking fern for the rest of the year. And I slept two hours last night and missed dinner. And Tracey's busy with quidditch, so the only person in the whole world to give a damn about me is a Gryffindor I've met for a week. Did I just say all that? No? Oh, good.

Daphne inhaled. "I've certainly been better. But I'll live. Thanks."

"That's alright. It's nothing to do with what happened with Malfoy?"

"Malfoy doesn't exactly lift the mood. But no, not this time. I've been tending to a Peruvian giant nirnroot."

"Oh, the plant that's been theorised to create anti-magic basins in the Amazon?"

"How in Merlin's good name did you know that?"

"I read it in a book."

"Just say you read my mind next time – it's more impressive, and I'd believe you." Seeing Granger's odd look, she added, "I meant that as a compliment. Sorry Granger, I'm tired."

"Don't worry. Are you sure you're alright? I won't mind finishing the patrol alone."

"I'll be fine. It's the nirnroot's fault. They give you headaches, you know."

"Really? Does that have to do with its magic-absorption properties?"

"Professor Sprout thinks so. But it's such an odd plant that it could just be another one of its annoying side-effects. Apparently the native Amazonians…" Daphne paraphrased Professor Sprout's lecture. Granger listened with rapt attention, and perked up when Daphne brought up the plant's possibly otherworldly origins, though regrettably Daphne had nothing to add to the conjecture. With the benefit of headache-free hindsight, Daphne had to admit that the nirnroot was truly a fascinating plant, and regretted her earlier lack of enthusiasm. Perhaps its magic-repellent nature might also have medical applications?

"I would think so. It could probably be used to absorb the effects of dark objects and the like."

"Did I just say that out loud?"

"Yes, you just asked if the nirnroot might have medical applications."

"Oh."

"Don't worry, I get that too, you know. My thoughts go faster than I can put into words, and I have no idea what I said and what I didn't. But about the nirnroot – I wonder how you'd isolate the anti-magic property. You probably can't just dice up a leaf and put it in a potion, since the whole point is that it resists magic, which would include resisting magical essence extraction. Hmm. That's such an interesting problem."

"You went quite a few steps ahead of me there. But no, I don't suppose you can just brew up a nirnroot leaf potion, in the same way you can't just cast geminio on an orichalcum ingot and bankrupt the goblins."

"I suppose. Magic does have its limits."

Daphne took the chance to ask Granger her earlier question on how muggles managed large-scale food production without magricultural methods, and was treated to a disquisition on underground irrigation, indescribable machinery, and selective crop manipulation by changing individual qualities with techniques too small for the eye to see. Perhaps the muggles had some sort of magic of their own, which Daphne would be curious to study if weightier matters did not presently demand her fullest attention. Nonetheless, Daphne could feel her fatigue draining away, and was again sorry to part ways with Granger when midnight came.

"Oh, Daphne?"

"Yes?"

"There's a saying from a famous muggle book: 'do not worry about tomorrow, because tomorrow will worry about itself. Every day has enough trouble of its own.'"

"I'll keep that in mind. Thank you, Hermione."