The next Thursday afternoon I was, as McGonagall had warned, set up in a spare classroom trying to see if students that were having trouble with wand magic might have an affinity with my style. The mostly-empty stone room had only a few uncomfortable wooden chairs, a table, and, unfortunately, a window with a view of the lawn.

"Aw, I should be out there, showin' off me flyin'!" complained Seamus Finnegan, his face pressed almost against the window. He was a tiny Irish first-year with bowl-cut black hair and mostly-missing eyebrows. Apparently, his early attempts at wandwork and potions were extremely prone to fiery explosions.

"I should be out there with my house instead of stuck with a bunch of Gryffindorks," whined Millicent Bulstrode, hunched in one of the chairs. She was a moon-faced, dark-haired girl with a pronounced jaw who already had a couple inches of height on most of the boys in her class. McGonagall told me to do what I could; rather than explosions, she wasn't getting much of anything from her attempts at casting spells.

"Well, personally, I'm quite happy to get out of physical education for something more interesting," proclaimed Hermione Granger, who was already at the head of her class for wand magic, but had somehow convinced McGonagall that she should sit in on this rather than have to take flying lessons with the rest of her year.

She wouldn't explain how, but McGonagall had found a bunch of non-wand foci somewhere in the school's storage, and I'd kept several of them. I was reasonably certain I understood what they'd been designed for, and was able to produce some miscellaneous spells with them. The others had been either too old or too obscure for me to risk putting in the hands of 11-year-olds.

I set out the three foci I'd found that seemed designed for light: a copper rod about the size of a pen that was covered with verdigris, a palm-sized circular steel-and-tin amulet with a quartz crystal mounted in the middle, and an honest-to-history Edison-style light bulb with runes etched along the base.

"I know it's not fair, Finnigan," I began, grabbing his attention and motioning him to take a seat, "but I don't particularly want to be here either, so the sooner we get through this the sooner we all get back the rest of our afternoons." The boy grudgingly took a seat, and Hermione sat up in hers at attention. "The only charm you're supposed to have already had was the light charm, right?"

"I've actually had a lot of success with several charms in the textbook including–" began Hermione, before Bulstrode cut her off.

"He means what have we all learned, mu– Granger, not what you've been prissing about in class," the stocky girl said cuttingly to the over-eager muggleborn. "Yes, wand-lighting is the only charm we've been taught yet. I hear Finnegan set his wand on fire."

"At least mine did somethin', ya harpy!" shouted the Irish boy, surprised at being brought into the fight with Hermione.

Before they could get into a petulant three-way argument, I grabbed the light bulb and shouted, "Lumos!"

The flash of brilliant white light from the now-lit bulb got their attention. I was going to have to send a very sarcastic thank you note to McGonagall for including house rivalries in my involuntary volunteer teaching time.

"Thanks for the answer," I snarked, "Can we do the lesson without trying to get into a fight every five seconds?" Three tiny heads gave petulant nods, so I continued. "This is a purpose-built focus. The three I've set out can do the light charm and possibly some other similar spells. Unlike your wands, which have to be complicated enough to produce any spell, these are much simpler enchantments.

"The first part of that is materials. Your wands are rare woods and exotic cores, each carefully attuned to your magical signatures. Purpose-built foci are a lot cheaper to make, and often work well for anyone that knows the spell.

"But the bigger benefit is that you can usually do without wand motions, which is probably what's tripping the two of you up. I never had any talent for getting them right, either. Wand motions are because wands are general tools, and you have to align their inner magical matrix with the matrix of the spell–"

"What?" Finnegan asked. Bulstrode seemed to be closer to getting it, and Hermione clearly wanted to explain it in exhaustive detail to the two.

Before the Gryffindor witch could start rapidly repeating the paragraphs from the textbook she'd likely memorized, I rephrased, "A spell is just a way of expressing your own inner magic in a way that happens to do what you want. It's like you're making an invisible web of energy, and if you get it shaped right, it does what you want. The spell words and foci are all just ways of helping your mind create that pattern."

I set down the light bulb, which winked out when I let go of it. I'd had to work hard the last couple of nights to get this trick down, and I summoned up my magic, visualized what I wanted from the simple spell, and wordlessly passed energy into my hand. It was much dimmer than the bulb, but a flickering light was clearly coming from the palm of my hand. Hermione's eyes grew wide because she knew how hard that was supposed to be, but at least the other two looked mildly impressed.

Closing my hand and ending the spell, I continued, "You don't actually need the focus or the words, but it makes magic a hell of a lot easier." Hermione looked very slightly offended at the curse word, but it didn't bother the other two, who both seemed like the type to curse up a storm in private. "But, anyway, since the wand is a general tool, making the right motion is important to getting your mind and the tool to agree on the shape of the magic you want to make. Specific foci, like these, already have that part of the spell matrix embedded in them. Think of it as already having the wand motion built in. You just have to do the rest of the spell. So, I guess, everyone try visualizing your intention like Flitwick taught you and saying the spell word."

Seamus grabbed the light bulb, having already been shown it worked. Millicent took the amulet, and Hermione grabbed the copper rod. It actually took Hermione a moment to get it to light up, fighting her urge to make a wand motion. The lighting charm didn't have much of a motion, but it was still present and could potentially misalign a focus.

Not long after the precocious muggleborn, the other two managed to produce light from their foci, to their obvious delight. "That was much easier!" exclaimed the boy, and the Slytherin witch couldn't help but nod in agreement.

I was now looking at probably taking on part-time apprentices. I'd almost been hoping they wouldn't have been able to get a light with these either. Oh well, maybe I could talk McGonagall into giving me some token payment if this became a regular thing. Being flat broke was really cutting into my ability to make long-term plans. "Good job. I don't want to make you think they'll all be this easy, though. The light charm is still one of the simplest possible spells, which is why you learn it first.

"For more complex spells, there might be some rudimentary motions necessary, and if you're using a focus made by someone else it may actually take some trial and error to 'feel out' what you have to do to get it to work perfectly. If you really get into this, you basically have to make most of your own foci, which is a lot of extra work on top of meaning you really need to take runes and maybe even arithmancy once you get to choose electives."

That brought Seamus and Millicent down a bit, though from her pleased grin I could tell Hermione had already planned to take those classes just as soon as someone would let her. "Did you know that so few students can do any spells without wands that it's a huge bonus to your practicals for your OWLs and NEWTs to be able to demonstrate that you can?" exclaimed the bushy-haired Gryffindor.

The two worried kids perked up a bit at that, and promised that they'd consider it. I was suddenly hoping that they agreed because it was very clear that after this I'd be training Hermione anyway, so I might as well get some kind of formal credit for it.

As we left the classroom, Mrs. Norris, Filch's cat, was curled up in a window near the end of the hall, soaking up the afternoon sunlight. "It's tha' terrible tattlin' beastie," groaned Seamus.

The two girls, to their apparent mutual chagrin, both exclaimed "Kitty!"

I smiled and said, "That's my friend, Mrs. Norris. She's a sweetheart if you aren't causing trouble for Mr. Filch. Do you want to meet her?" Seamus shook his head and headed back to his room, but the two girls were soon giving the skinny cat very thorough pets. Maybe this would work out, after all.