Ada's room was large and comfortable, furnished with old but finely-made wooden furniture and with thick velvet curtains over a wide window, which looked out over the college grounds. Today the curtains were drawn and some of the furniture had been rearranged, to create an open space in the part of the room furthest from the door—which was covered in thick black fabric, hanging from a series of hooks Ada had put in above it. On her dresser was a tray filled with an assortment of food, and beside that were three jugs; one of water, one of milk, and one of apple tea. She also had a medical kit handy, a large bottle of ligament rub, and two buckets of water.

Heart beating fast, Ada took off her glasses and put them on her dresser, then walked to the centre of the space she'd created. Control, she thought. Stability. Focus.

Hands raised and steady, Ada pictured a dam, holding back a huge amount of water but letting just a little through. She focused on the memory of a tree being felled, one of those in the college grounds that had grown too large to be safe, the way it had fallen, so slowly at first, almost hanging in the air, before suddenly crashing down. She pictured herself, pouring oil from a flask into a vial, the steady flow of liquid from one vessel to another.

There was a swell of energy which Ada immediately struggled to hold back. I can't possibly fight this, she thought, immediately following that with, no, wrong thinking, this isn't some alien force, this isn't some bizarre outside influence. This is me. Just me.

Ada clicked her teeth together, then she made two fists. She brought them together, then extended her index fingers to touch each other. Slowly she pulled them apart, suppressing a yelp as a little spark jumped from one finger to the other.

"Good," she murmured, and she rubbed her sweaty hands together before bringing them up again, a little way apart. Lightning sparked between her palms with a short sharp snap.

"Okay," she said, lowering her hands once more, her voice breathy with excitement. "Okay, okay."

Despite the thrill she felt Ada forced herself to take a break, have a glass of milk, eat a biscuit.

"Next," she murmured, back in the open space, her eyes on a lamp fixed to the far wall. She raised her hand, which was trembling only very slightly, and she concentrated.

As Ada lay on the floor, staring up at the ceiling, she attempted to reconstruct the events of the last few seconds. She'd felt the energy build up, as before. She'd suppressed the urge to fight and experienced that thrilling sensation of control. After that she'd felt a physical shock in her arm and her chest, like she'd been punched hard, and there had been a bright flash and a loud noise, and—

Buckets, Ada thought, as she sat up. She looked at the two innocent buckets of water she'd filled earlier, then crawled over to them and pointed her finger at the water inside. She concentrated, felt the energy, smiled as a spark jumped into the water. Okay, she thought. So ... so lightning likes water more than metal? Or were the buckets closer than the lamp?

Ada pushed herself up and smoothed down her dress. She took an apple from the dresser then went and sat on her bed.

Clearly, she thought, as she crunched into the apple, I've got a lot of work to do.