Lying in her single divan bed in the guest bedroom, Monica could barely sleep, her naked body twisting around in the sheets. Her mind was preoccupied. She couldn't get over how angry she felt that her mother had found out she'd been stalked. Which begged the question: why hadn't she told Maddy herself? Why didn't she trust her? Was it because her mother had always spent so much time with other people - mainly her clients - and never enough with her or Harley?The problem was also, she realized, that Maddy, like most people, never saw her as she really was. Her mother, though curious to learn about her problems, never tried to understand them, whether they were twinges of RSI from excessive keyboard work, or having a heavy period or getting her heart broken. It was almost like talking to someone who didn't speak her language, yet she always made an effort to understand her mother's concerns.

She sighed and twisted again in the sheets under the thin blanket. She could see through the parted curtains that the night was clear and starry, thanks to lo-glare lighting, even in such a gigantic city. She slid out of bed and approached the window. Hearing the sound of someone riding a scooter down the empty street, she looked out. The rider was a teenage boy who stopped directly under her window. He stood in his peaked helmet, letting his motor idle. Perhaps he's picking someone up.

On an impulse, she dressed in the dark and slipped out of her room. Downstairs everything was silent, and she tiptoed to the front door. Peering through the letter flap she saw Harley, in a green parka and scooter helmet, flit out from a side door and rendezvous with the rider. He straddled the pillion and they moved off down the deserted street.

Opening the door and following the front path through a patch of grizzled dead hydrangeas, she reached the sidewalk and summoned her rental car. She had a pretty good idea where Harley and his friend were going, and was soon in the car and picking up speed.

She sat in silence for a while, before tuning in to her ajna. Her thoughts were on the illegal night flight she knew was about to take place. Just as her best source of information for mainstream news and events were the dozens of audio and holo channels streaming in, so the best way to be sure she was heading for the right place was to access the so-called backslang channels - the unlicensed pirate or community stations that gave out hot tips on everything from Freestuff Markets, where 3D-printed goods were exchanged, given away or sold tax-free, to police drug-raid tipoffs.

To open this gateway to the street world she needed to know the password. It was no use her simply saying "Play" and going through the menu of options, she would have to get smart. The password was changed every day and having no friends in the criminal underworld to seek advice from, she knew it would be challenging. She had one clue, obtained from one of the nerdy data-crunchers at the lab who had told her he used the backslangs when hunting down hot VR holos. He had told her that after uttering the word "Play" to tune in her ajna, she should say the word "No" before every command she gave.  Then, at the end of the last option on the menu, a scrambled word would be uttered that she would have to unscramble. That was the password. He also told her it would be easy, as the only people the backslangs were trying to outwit were the police, who weren't considered very bright.

Following his instructions, she repeated the word no until all the options were exhausted. There was a pause, and a mechanical voice said something like the words Gavroche and Dartford. Monica turned the words over. Gavroche was the street urchin from Les Miserables, a ragamuffin, a gamin. How that fitted with Dartford she hadn't a clue. Then she remembered the supernerd telling her the password was always a phrase and one of the clues was a word that sounded like part of the phrase. Gavroche didn't sound like any word she'd ever heard, but Dartford certainly had possibilities. Synonyms for urchin raced through her mind. The only one that stuck was artful dodger, the first word of which sounded like Dartford, so she gave it a try.

"Artful dodger" she said to her ajna, and was greeting by a barrage of radio static. A cacophony of crackly voices could be heard giving out bursts of information. She waited until words similar to night flight were uttered.

"Night flyers are in for an Olympian treat tonight with enough fun to keep a queen happy. The race is on. The Dogs of the Air are taking on the Kings of the Air in the skies above East London. Only the bravest will survive, to use a hackneyed phrase. No, this one definitly ain't for marshmallows."

"Stop," she said. She had enough clues to guide her route. She told her rental to head for Queen Elizabeth Stadium in Hackney Marshes.

Monica told her EM car to go at the maximum speed limit, feeling a slow tingle building up in her spine as she rode the dark Stream. At night the Stream with its branching Streamfeeds, the only permitted route for EM vehicles, turned into a long, glistening grid of fluid light. Red and silver ribbons flashed past her, gleaming like fireflies, as more and more cars joined the eastward flow, like fish swimming in a black sea speckled with twinkling headlights.

She tuned in to her ajna once more to catch some of the trash talk among the audio jocks rapping about the big race. She wanted to learn more about this alien world that Harley was so attracted to. One jock said the whole of East London would be watching the race, even though it was highly illegal. Another predicted that police copters with penetrating searchlights and loud hailers would break up the party before the race ended. According to a third, the boarders who were taking part had all trained hard, but tonight they were riding by the balls.

The race was due to start in thirty minutes, when at a signal the teams would rise en masse from an empty cement swimming pool. The pool had been part of the 2012 Olympics, then abandoned, roofless and open to the elements, until construction teams who were fans of flyboarding dug it out of the rubble and resurfaced it for skyracing. Fitters, welders and even painters had completely renovated the seating arena to allow for thousands of spectators. Monica looked down, and could tell from the lights and the noise that the abandoned Olympic stadium was directly ahead.

Screaming hardcore anthems blasted out of giant speakers and Monica told her car to hover a hundred meters above ground at the top of the Stream. She was content to watch the action from half a kilometer away and not venture any closer. There seemed to be a lot of drug-infused, sweaty, excited energy emanating from the massed crowds in the banked walls of seats around the pool. Suburban teens and scruffily-dressed street people jostled together. Men with hair down their backs sat next to shaven-headed fitboys who were famous for doing group press-ups in the street. Flyboarding was considered the ultimate extreme sport and deaths were not uncommon. Fans had come from all over the country, expecting a hard-fought race.

Two teams were waiting in the cement arena, one team wearing purple flying suits and sneakers, the other in yellow. Every racer wore a sweatband containing an ajna headset for team communication, and many of them fidgeted as they stood on their boards and gripped their tiller-attached consoles. The Dogs of the Air from the London area were challenging a team from Manchester, the Kings of the Air. Monica wondered whether Harley and his friend were among the crowd ranged around the pool.

A flurry of searchlights criss-crossed the sky above the pool, converging to form an area a hectare square. A honking horn sounded, accompanying a whooshing sound produced by the speakers to add pizzazz. The boarders became airborne and were soon flitting like moths in and out of the searchlights. To Monica it seemed balletic, like figure-skating in the sky, and she wanted to be out in the air with the swooping, swerving flyboarders. Then the boarders juiced up their magnets and began to move up fast. The two teams created a vortex spinning around an invisible racetrack in the converged searchlights.

There was room for upward and downward movement in the vortex. Several riders broke from the pack, spiraling upward before straightened their boards into head dives, the verticality giving them increased speed. They bent their boards, after a blast of forward motion, to send them dipping and zipping ahead of the group. Others were angling their bodies to produce tight turns that outpaced their competitors. The best technique for increasing speed was to streak down from a high altitude and turn the steering magnets upward, using the g-force to shoot the rider up like a rocket. The trick was to avoid speeding down so hard that gravity made the drop impossible to pull out of. Skilled boarders tracked away from the group and forged their own paths. Their aim was to maneuver into the magical first position that led to victory.

Four boarders streaked away from the pack, leaning hard on their tillers, aiming for maximum separation, and Monica realized with a chill that they were all in the zone, totally going with their intuition. Other boarders were breaking away, one leaning into a high-speed turn and shooting straight between two slower boards.

Each boarder had only a fraction of a second to react when another was coming close to his board. At the speed they were going, if one board hit another it would break it in two. A mid-air collision would send both riders tumbling down. Boarders were now passing each other at eighty kilometers per hour. To succeed you kept your nerve, to fail you rocketed down onto hard concrete hundreds of meters below.

Mercifully, no rider slammed into another and nobody went into free fall. The winners were announced as the London team, to mighty roars from the crowd, and the racers drifted downward. Monica had seen enough. She told her car to head back to Hampstead Lane.