He had written it out the night before.
Not because he needed to — the eidetic memory meant that lists lived in his head as clearly as they would on paper — but because there was something useful about the physical act of organizing priorities in sequence. Writing a list was a form of commitment. It forced decisions about order and about what mattered enough to be on it at all.
The list had seventeen items.
He went through it now, sitting on the edge of his new bed in the blue room, while the Burrow settled into its morning sounds around him — his mother in the kitchen, the particular clatter of a household that had always been large and was now more comfortable about being large. Outside the window, the garden that was becoming something more serious than it had been was already occupied by Pip, who had opinions about the morning watering schedule and implemented them with quiet conviction.
Seventeen items. One day in Diagon Alley. He had organized them by district and by dependency — things that needed to be commissioned before things that needed to be collected, things in Knockturn Alley grouped together because going twice was inefficient, things that required conversation separated from things that required only payment.
His mother was coming with him for the first part of the morning. She had her own errands — potion ingredients for the garden business, which was now generating enough consistent interest that she'd needed to expand her stock — and he would meet her for lunch at the Leaky Cauldron before the afternoon portion of the list, which he would handle alone.
She had accepted this arrangement with the careful neutrality of someone who had decided to extend trust and was monitoring the results.
He pocketed the list, picked up his current trunk, and went downstairs.
Diagon Alley received them the way it always did — with the organized chaos of a commercial street that catered to an entire magical community and had strong opinions about doing so loudly. The summer crowd was in full force: families with first-years buying their initial supplies, returning students updating equipment, the general population going about the business of a world that ran on different principles than the one immediately outside its entrance.
He moved through it with the calm attention of someone who knew where everything was and what he needed from each place.
First stop: Gringotts
He withdrew what he needed for the day in a combination of Galleons and the smaller denominations, organized in his current money pouch which was adequate but not what it was going to be by the end of the afternoon. He also checked the account balance — not anxiously, but with the practical habit of someone who believed in knowing exactly what they had — and confirmed that the investments his mother had helped him set up the previous week were properly allocated.
Two hundred and seventy thousand Galleons, minus what had already been spent on the Burrow renovations and the initial shopping.
Still an extraordinary amount. He intended to be careful with it, not because he was afraid of spending it but because being careful with resources was simply correct practice, and he had enough engineering background to understand that the difference between a project that succeeded and one that didn't was often whether the person running it had maintained adequate reserves.
He withdrew three thousand Galleons for today and left the rest exactly where it was.
The trunk came next, because everything else would eventually go into it.
The trunk-maker's shop was on the quieter end of Diagon Alley, past the point where the family shops gave way to the more specialist establishments. The sign was unassuming. The interior was not — it had the organized density of a place that took its work seriously, with sample trunks on every surface in various stages of completion and a smell of treated wood and leather and the specific metallic edge of enchantment work recently done.
The trunk-maker was a witch in her fifties who had the specific calm of a craftsperson who had long since stopped needing to impress anyone. He had owled her two weeks ago with his specifications and she had owled back a confirmation and a price, and the trunk was ready when he arrived.
Five compartments.
The first for wardrobe — fitted with cedar lining and a climate charm that maintained the specific conditions optimal for clothing storage. The second for potions: temperature-regulated shelving, ventilation charms, separated storage for ingredients, materials, and completed potions with appropriate containment for volatile substances. The third for books, with humidity control and the specific lighting that was optimal for reading without causing page deterioration. The fourth for his future Pensieve and memory storage, fitted with a stabilizing base and individual slots for memory vials, organized in the system he'd specified. The fifth miscellaneous, with a secondary locking charm he'd asked to have integrated into the trunk's own mechanism rather than added externally.
And on the outside, along the base: a broom holder. Two loops of reinforced dragonhide, fitted with securing charms, sized for standard broom handles.
He examined it thoroughly. He opened each compartment and checked the enchantments with the hawthorn wand, feeling for the quality of the work. He tested the locking mechanism on the fifth compartment. He checked the broom holder's securing charms.
Everything was exactly as specified.
He paid without negotiating, because the work was correct and the price was fair and he had no interest in treating a craftsperson's honest work as an opportunity to spend less than it was worth.
The trunk-maker helped him transfer his current belongings into the appropriate compartments while he organized them, and he took the opportunity to arrange each section properly rather than simply moving things across. Books by subject and then by level. Potions materials organized by category. The basilisk fang and the venom vial and the notebook and the length of basilisk hide into the fifth compartment, locked.
"Good trunk," the trunk-maker said, when he was done.
"Good work," he said.
She nodded with the satisfaction of someone whose assessment of their own work had been confirmed by someone who'd actually looked.
The pensieve came from a specialist shop three doors down that dealt in memory-related magical instruments — pensieves of various sizes, memory extraction equipment, storage solutions, and the associated accessories of a practice that required precision tools to do correctly.
He had thought about the pensieve carefully before deciding to buy one.
The argument for was straightforward: he had access to two complete sets of memories — his own previous life and Ron's — and the ability to review them in a pensieve with the clarity of full sensory experience rather than simple recall was useful in ways that justified the cost. He also intended to use it for the purchased memories, which were going to constitute a significant learning resource and which he wanted to be able to revisit accurately.
The argument against was that he was thirteen years old and a pensieve was an unusual piece of equipment for a student and might raise questions.
He resolved this by keeping it in the locked fourth compartment where no one who wasn't specifically invited would encounter it.
The pensieve he chose was not the largest available — not the grand stone basin of Dumbledore's design — but a practical personal model, shallow enough to be efficient, deep enough to work properly, made from a silvery alloy that had the specific quality of something that had been made to last rather than to impress. It fitted neatly into the fourth compartment's stabilizing base as though it had been designed for it, which it had, because he'd sent the trunk-maker's specifications to the pensieve shop when he'd placed the order.
He bought the memory extraction tool as well — a fine-tipped instrument for drawing memories cleanly from the temple without distortion — and a set of fifty blank memory vials.
The memory section of the general magical goods shop was his next stop.
It was in Wiseacre's, which he'd known primarily from Ron's memories as a source of school equipment but which turned out, on the upper floor, to stock a curated selection of educational memories. Not the deep personal variety — those couldn't be sold without consent protocols that made the process prohibitive — but the constructed educational variety: carefully assembled memories of expert practitioners demonstrating skills, available as a teaching resource for self-directed learners.
The selection was organized by subject and level.
He worked through it methodically.
Potions memories for years one through five, with particular attention to the third and fourth year material that he hadn't yet covered and the fifth year content he wanted to preview. The demonstrator in these was a Potions master he didn't recognize whose technique was — watching the memory index description — precise and well-explained. He bought the full set.
Charm work, years one through five. The same principle: he had reasonable first and second year practical coverage from the Room of Requirements work, but having expert demonstrations of the spellwork available for review was different from his own practice and complementary to it.
Defense Against the Dark Arts — more selective here, because the subject had been inconsistently taught for long enough that the quality of available memories varied significantly. He bought the theoretical content and the specific memories flagged as demonstrating canonical spell-work, and skipped the ones that appeared to have been assembled by practitioners with views he found questionable.
Transfiguration, full set. This was the subject where he was most conscious of a gap between theoretical understanding and practical fluency, and expert demonstration was likely to be the most efficient bridge.
He did not buy Divination memories because there were no Divination memories worth buying, and he did not buy History of Magic memories because Binns's approach to his own subject was adequately represented by the textbooks and adding his voice to the experience would not improve the content.
He paid for the full collection, transferred the memories into his vials with the extraction tool according to the shop's instructions, organized them in the fourth compartment by subject and year, and closed the trunk.
Forty-three vials. Each one a session of expertise he could review as many times as needed, from the inside, with full sensory clarity.
He thought about the months ahead and felt, with quiet satisfaction, that he was building something solid.