Bryony turned off the burette tap. “Well, that’s something new.” She looked up at the big grandfather clock at the end of the lab. She hadn’t been working for more than fifteen minutes yet. The mech could wait where it was, on the end of the varnished wooden bench, so she went back to her glassware. She’d rotated the burette so that she could titrate right-handed — or was that titrating left-handed, since although she was turning the tap with her right-hand, you used your non-dominant hand for that? She wasn’t sure, but it didn’t really matter. She focused on letting just a tiny drop fall from the burette tap and watching the colour of the solution in the beaker below. With the final drop, the solution changed from violet to a pinky red. Bryony whooped and climbed onto the lab stool. The liquid still filled too much of the long thin pipe for her to take a reading from floor level, but it was simple enough to read off the height from atop the stool. When she had recorded the number in her notebook, she reclaimed the mech from the far end of the bench.
She certainly wasn’t expecting a message. In fact, she was a little surprised that anyone wanted her so urgently that they’d send a mech. She supposed she’d better have a look at it before carrying on with the titrations, though. Perhaps it just needed charging. Nothing happened when she connected the mech to the charging point under the lab bench, so she picked it up and popped its head open.
“Yikes!” The battery cell had cracked open and gooey liquid was leaking out of it. Bryony pulled open the cupboard beneath the bench and grabbed an empty beaker to dump the leaky battery into. Then she used an old rag and the end of her spatula to get the rest of the goo — at least what she could see of it — out of the mech’s head cavity. Fortunately it didn’t seem to have got as far as the memory tapes. That would have left things pretty much unsalvageable.
It was bizarre that anyone would let a mech go out with a battery in condition to crack like that. Didn’t people have safety procedures for that kind of thing? The battery must have been ancient. It wasn’t a standard issue postal service mech battery either, so replacing it wouldn’t be trivial. Not that it would stop her from rigging something to last long enough to figure out what was going on.
All a battery really did was to stimulate the flow of electrons through the circuit. She could make something close enough to work for now. She rummaged in her stripy tote bag for a pencil. Then she took another beaker and some aluminium foil from the cupboard below the bench. She walked down the lab to the storeroom at the back to find salt. The dials on the lock turned smoothly and the door swung open. She wasn’t sure if she was technically allowed to have the code, but Mr Andreyev didn’t mind her using a reasonable amount of supplies for her experiments. The salt was on the first shelf from the door; Bryony took the hefty brown sack back to her lab bench, carefully locking the storeroom door behind her.
She dissolved the salt in a beakerful of water. Bryony wondered how often she thought of dissolving as breaking something into its electrically positive and negative parts, as she stirred the salt water. Not much more often than she wanted make an electrolyte solution for a battery. Batteries made salt water a lot more interesting. She tore off a long strip of aluminium foil and folded it over the side of the beaker. The carbon pencil went into the salt water on the other side. By dint of holding the mech upside down in one hand and splaying the fingers of her other, she managed to connect the makeshift electrodes to the battery connection points in the mech’s head cavity. The mech’s eyes glowed dimly and a faint grinding sound emerged from its interior.
“Oh plagues and pestilence! How many of these things am I going to need?” She did some mental arithmetic, wiped her hands dry on her tie-dyed t-shirt and pulled three more beakers out of the cupboard. Several minutes and several pencils later, the lab bench held an enormous, if not especially powerful battery, electrically connected by long strips of aluminium foil. She would have to replace that for Mr Andreyev, Bryony thought, since it was rather more than a reasonable amount. Not that it mattered! Her curiosity about what the mech would say had been growing. With no little excitement, she attached her battery’s electrodes to the mech. Its eyes lit up. Gears whirred inside. Faintly, but unmistakably, it began to deliver its message.
“Greetings, student. This message serves as an offer of a place at the Mechatropolis Academy for Mathematical Sciences. We await your response with the return of this mech.”
Bryony whooped loudly enough that she almost expected half the school to arrive and demand to know what had happened. Disappointingly, nobody appeared. The Academy! It was the kind of thing people dreamed of. And she was going to be a student mathematician — just as soon as they had her response. She was halfway down the laboratory when it occurred to her that leaving the bench in its current state would bring down the wrath of not only Mr Andreyev, but of any self-respecting person who saw the mess and potential for chaos.
Bryony calmed down a little in the course of her tidying up, but she was still whistling cheerfully as she began the walk to the lift shafts and, from there, the Academy.