"Hey, kid!" Leo grabbed Hilly by the elbow and towed her unresisting friend over to where a small, dark-haired boy was sitting cross-legged, methodically dismantling the Puzzle with a scowl of intense concentration. The Puzzle had been there forever; Leo could remember poring over the pile of wooden blocks herself, their curved and recessed surfaces polished by generations of inquisitive hands, hesitantly removing one here or there to replace it elsewhere in the mass in the hope that it would begin to take on a recognisable shape. That had been last year, when her newly-arrived status at the Outer Zone School of Science had allowed her to flout the school's more established protocols without earning more than a mildly disapproving tut from the Senior Scientists. Now, older and with the profound wisdom of an entire year behind her, she felt it was her bounden duty to share the fruits of her learning with the visitor.

"My name isn't 'kid'. It's Ambrose Goldstraw." The boy didn't look up from his contemplation of two ostensibly identical blocks, but his scowl faded and he bit his lip. He weighed the blocks, one in each hand, and finally put one down on a growing pile at his side, the other placed in a lonely patch of floor on its own.

Leo glanced sidelong at her friend, who grinned and shrugged. "So who're you visiting? I don't recall any Goldstraws - you got a big brother starting here this year? A sister?" The boy shook his head. "One of your parents working here?" That was probably it - there were cleaning and kitchen staff that lived in, and some of them had families, although they usually stayed out of sight in the Service accommodation, down at street-level.

"No..." With the immediate dilemma of distinguishing one block from the other past, the slightly worried look was deposed by a mercurial smile. "I'm here to study!"

"How old ar-" The boy rolled his eyes, exasperated, and Leo put a hand to her mouth at the expression, which looked like it belonged to a much older face.

"Nine." Leo and Hilly exchanged amused glances, and Hilly plonked herself down on the floor, careful not to displace any of the blocks Ambrose had sorted.

"Aren't you a little young to be starting school?" By which, of course, she meant proper school, Leo knew. No one at the School really counted the City's small General schools as anything more than a basic grounding in Reading, Writing, Maths, and Having your Hair Pulled by Bigger Kids. If you wanted to go further than that, it was up to you to find someone willing to take you on and train you. A patient employer, private tutor, or - Leo shuddered - there were places like the Secretarial College, where her sister had gone to learn shorthand and smiling politely at the boss's weak witticisms, and manhandling the heavy iron-and-brass typewriters without chipping a nail.

And as for the Country schools, who knew what they taught? Proper care and handling of pigs, or corn-picking or something, probably. She hid a little smirk and sat down opposite Hilly, who was gleefully taking pieces out of the Puzzle under Ambrose's enthusiastic direction. The two girls swapped another glance and, with that uncanny understanding they seemed to share, conversed briefly over the boy's head.

What are you doing? You can't take it apart - it's the Puzzle!

Relax... if anyone asks, the kid did it. And he doesn't know any better.

Leo regarded the boy, separated from her by the impossible gulf of three years, and felt a twinge of guilt. True, the Seniors probably wouldn't do more than give him a longsuffering sigh and, perhaps, mete out a stern but kindly lecture about 'establishment' and 'protocol', but he'd would probably be ragged about it by his classmates for years if he took the Puzzle apart competely. There were Senior Scientists - Court members, even, who'd been around when the Puzzle had first been presented to the school by the old King's Master of Crafts, still glowing redly in its varnished newness. It was ancient. More than that - it was Tradition.

"Look, k- Ambrose, I don't think this is such a good idea. We don't take the Puzzle to pieces." Ambrose paused, a collection of s-shaped hooks of wood clutched haphazardly to his chest.

"Why not? It comes apart - look!" With his free hand, he plucked another piece indiscriminately from the mass and waved it expansively before setting it down - another new pile, distinct from the others even though it looked to Leo precisely the same as any number of the other disassembled blocks.

"It's not made for taking apart. It's made for..." She gestured vaguely "...for putting together. For solving. Taking it all apart's just silly." Ambrose gazed at her, perplexed.

"Then why are you helping?" She glanced down and blinked at the sight of a little block, an overfed cube with convex sides, nestled comfortably in her hand. Did I just... And in the back of her mind, a gleeful voice piped up Of course you did - you've been wanting to do this ever since you first saw the stupid thing. Beaming, Ambrose pointed at an empty patch of floor and she obediently deposited the block there, trying not to grin. We are going to get into so much trouble... But as the outer layers were gradually stripped away, revealing tantalising hints of shape, she began to lose herself in the task.

"Okay, but if anyone shows up, this was your idea."

Ambrose shrugged, apparently unconcerned by the possibility of consequences. "I couldn't rat you out if I wanted to. I don't even know your names."

"Leona Rush, and this is-"

"Hilly Torrance" the other girl broke in, before Leo could finish. "It's short for 'Hilary', but no-one calls me that unless they like being stuffed down the laundry chute." She ran a hand through her hair, giving her the appearance of a particularly cheerful haystack, a marked contrast to Leo's burnished darkness. "You think you can remember that, kid?"

Ambrose shot her a look so old-fashioned that it almost coloured the air sepia, and Leo snorted indelicately, turning away to ease another block out of the diminishing Puzzle and listening with half an ear for approaching footsteps.

"It's not 'kid'. It's Ambrose. Think you can remember that... Hilar- um. Hilly?" She laughed and punched him lightly on the shoulder, and he gathered up an apparently random handful of blocks, and thrust them happily into her hands. "Okay, lock these all together to make a sort of -" he gestured, drawing a small arc with his fingertips, "- like that. You can see how they match up - there's a sort of pattern if you get the sunslight on them just right." Hilly bent over them, trying to catch sight of the purported pattern, and Leo did the same, turning the piece of wood - a long, thin cone - in the long, faded shaft of light where it fell, printing the stained-glass stars and cogwheels of the Science School crest onto the cool marble tiles.

There, was that something that might have been an intentional design, or just the natural grain of the wood? No - she decided - if there was any sort of pattern there, it was in the boy's head and nowhere else. But still, the assorted segments Hilly was beginning to piece together seemed to fit with an oiled smoothmess that suggested they'd been made for each other, twisting and locking with soft, definite clicks. The blonde girl looked up from the assembled puzzle fragment, impressed, her fingertips tracing its delicate swan-neck curve.

"I think you're onto something. How'd you work that out?" Ambrose gazed at her blankly, as if he hadn't understood the question.

"They - well, they fit together." And then, gnomically, "It's the way of things." Leo swapped a bemused glance with Hilly, then steeled herself to dismantle the last parts of the puzzle, four interlocking shapes that still glowed, gold and red, their varnish bright and scarcely worn. Ambrose shook his head.

"Not those. They can stay. Four's a good number." Whatever that means. Leo thought, but she left the pieces alone; four tapering curves of less than a hand's span in length each, and notched and pierced like deformed wooden whistles. It wasn't until later that day that she would consider it slightly odd how easily she'd given in to his instructions; she was - as her school reports regularly documented - strong-willed, opinionated and argumentative to a point where some of the Senior Scientists hesitated to ask 'does anyone have any questions?' at the end of a lesson. Of course, by then too many things would have happened for her to dwell on it for long; the run-in with Raines, the summons to the Library...

She knelt down amidst the puzzle pieces, simultaneously nervous and eager. "Come on then, genius. What are we gonna make?"

Ambrose regarded her from beneath a tangle of dark curls, his eyes aglow with the sheer delight of creation. It was an expression that she would come to associate with him over the course of the next few years.

"Something wonderful."

And they did.