He shook his head. "Not anymore."

"Because I made one mistake?"

"It was more than a mistake, Kat." His eyes narrowed. "You knew exactly what you were doing."

"I was scared. I didn't know what else to do."

"That's not the point. It still happened, and it shouldn't have."

"And so you're cutting me out of your life?"

Victor leant forward, jabbing a finger at the screen. "I'm doing more than that. I'm warning you to stay away from me. Give up this stupid race. You can't beat me to Djatt, and you shouldn't try."

"Are you threatening me?"

He shook his head. "You're not up to this, Kat. You don't have what it takes."

"And you do, I suppose?"

He sat back. "All I'm saying is that we threw you through a door with air on the other side of it. The next crew you piss off mightn't be so thoughtful."

> Incoming call from Feliks Abdulov.

"Fuck off, Victor."

She cut the feed, hands shaking. The screen blanked, and then fired up again, this time showing the head and shoulders of her father.

She swallowed away the sudden prickle in her eyes, unclenched her fists.

"Hello, Dad."

"Katherine. Are you okay? You look upset."

"I'm fine." She gave her best approximation of a brave smile.

"Well, you don't look fine. But then, I guess I've had better days myself."

She looked into his face, still dirty from working on the Ameline's hull, trying to memorise every crease and wrinkle.

"I wish we'd had more time to talk," she said. There was so much left unresolved. "Just promise me you'll still be here when I get back."

Her father reached out a hand. "Don't worry about us, Katherine."

"Dad, I-"

"Concentrate on your mission. There's no need to-"

The screen flickered and Feliks staggered. He put out an arm to steady himself. The lights above him dimmed to brown, and then came back up to full strength. Alarms sounded.

"Dad! What's happening?"

She checked her implant. Traffic control was offline. People were shouting all over the Quay. The walls of Bay 49 had buckled, rocking the station. They had been sucked inward and the blast doors had cracked, revealing the gaping vacuum left by the ship that had been resting at its heart.

Kat blinked at the pictures, unwilling to believe what she saw: the Tristero had gone. It had left the station without even bothering to wait for the blast doors to open, activating its engines while still wrapped in its docking cradle.

"Jesus," she said, "he jumped?"

CHAPTER THIRTEEN.

PRIME RADIANT.

"Hey, I found a sign!"

Kristin came running across the stone circle towards them, waving her arms, boots kicking though the long grass.

Ed Rico leaned out of the Land Rover.

"Where?"

"On one of the uprights." She stumbled to a halt and bent over, hands on knees. "An arrow."

When she'd caught her breath, she led them over to the stone. Sure enough, someone had scratched a crude arrow into its weathered surface. Ed traced the shape with his finger. It pointed to the arch on the right of the stone. The scratches were pale and gritty and rough to the touch.

"It's fresh."

"Sure is. No more than a week old, I reckon."

Alice said, "Do you think your team left it?"

The American woman rubbed the short white bristles at the back of her neck. "They must have done. It's standard operating procedure, if you have to leave a man behind."

She dropped to one knee and gathered her bagged samples of grass and soil. She stuffed them into the pockets of her cargo pants and stood, brushing the dirt from her hands.

"Are you ready to move?"

They waded back through the wind-ruffled grass to the Land Rover. As they walked, Alice reached out to touch Kristin's elbow.

"You know, you haven't told us who you work for."

The taller woman stopped.

"I haven't?"

She glanced impatiently back at the marked arch, shifting her weight from one booted foot to the other.

Ed rubbed his eyes. His skin itched. After sleeping in his clothes, he needed a shower.

"You're obviously military but you don't have any insignia," he said.

Kristin glanced down at her khaki hoodie.

"We're part of a joint UN recon team," she said. "I guess all the badges are on my jacket, in my kit bag."

Ed stepped forward. He felt the wind tug at his t-shirt. "You told us this was a one-way trip."

"It is."

"Then how can you be a recon team? How are you going to report back?"

Kristin folded her arms and puffed out her cheeks.

"We're not."

"Then what are you doing?"

Kristin turned and started walking toward the Land Rover, arms still folded. Ed and Alice hurried to keep pace with her.

"We're trying to prove a theory," she said. "We've mapped part of the network and we've used computer extrapolation to sketch in the rest." She kicked at the long grass. "Our model indicates an overall structure. As far as we can tell, the branches collapse toward a single point. We call it a funnelling effect."

Shuffling along beside her, Ed pushed his hands into the pockets of his jeans. "You mean, all the gates lead to the same place?" He felt a sudden stab of wild hope.

"That's right. All roads lead to Rome. According to the model, whichever route you take, you eventually spiral in towards the centre of the network. We call it the Prime Radiant."

Ed saw Alice's auburn hair flickering in the wind. He heard her say, "Like the canals in Amsterdam?"

Kristin raised an eyebrow. "How so?"

Alice brushed her fringe from her eyes. "In Amsterdam, the canals are arranged in semi-circular arcs. Wherever you are in the city, if you follow one, sooner or later you'll end up back at the Central Station. You can't get lost."

They reached the Land Rover. Kristin pulled off her hoodie and tossed it onto the back seat.

"It's more like a spider's web," she said. "Only we don't know what's at the centre."

"So you're going to find out?"

"That's right. That's our mission. And all our predictions point to that as the place we'll find all the people lost in the network."

Ed's breath caught in his throat. He felt Alice slip her hand into his.

"Like Verne?" she said, eyes shining.

Kristin nodded.

"We may be ten years behind him, but if we head for the Prime Radiant, we'll find him sure enough."

For the last three years of her life, Ed's mother had lived in a gated retirement community on the outskirts of Cardiff, paid for by her eldest son, Verne. When she died of pneumonia at the age of sixty-two, he, Ed and Alice were the only attendants at her funeral.

After the service, they crunched their way back along the shingle path to the crematorium's wrought iron gate. Behind them, the last scraps of smoke rose from the brick chimney. It was a bright day in the Valleys. Frost lingered in the gaps and shadows between the grave markers and fir trees. A single vapour trail scratched the high blue sky. Verne and Alice were wrapped in coats and scarves. As they walked, Alice slipped her arm through Ed's.

"It was a nice service. I'm glad you came. Shirley would have been pleased."

Ed had his fists balled in his pockets. He wore a black suit jacket over skinny dark jeans and a paint-stained Ramones T-shirt.

He said, "I'm sorry I was late."

Beside him, Verne had his head down and his shoulders hunched. He said, "I suppose we should be grateful you're here at all."

Ed stopped walking.

"What do you mean by that?"

Verne turned to face him. "What do you think I mean? You're always so wrapped up in yourself. When was the last time you bothered coming down here?"

"I saw her at the wedding."

"Three months ago! Where were you when she really needed you, eh?"

Ed bristled. His mother had been raised as a hard-working Valleys girl. She disapproved of his life as a penniless artist, and seldom missed an opportunity to voice her feelings on the matter. "I was going to come, you know I was. It wasn't my fault she died when she did. And anyway, where the fuck were you?"

Verne gave an exasperated sigh. He'd been in Mogadishu when Shirley died. "You know I would have been here if I could, if the rebels hadn't closed the airport. They were shooting Europeans. We had to stay hidden in the hotel. Whereas you, Ed, all you had to do was catch a train."

Alice slid her arm out from under Ed's.

"Verne, this really isn't the time."

"I'm just saying-"

"Well, don't."

She pulled the black fur hat from her head and shook her gloved fingers through her mussed, rust-coloured hair.

"I'm sorry, Ed," she said.

She took his elbow and walked him to the gate. Moss dappled the cracked concrete path. Verne's car waited on the opposite side of the steeply sloping street, in front of a row of terraced houses.

"Are you sure we can't give you a lift? We could drop you at Oxford and you could get a train back to London from there."

Ed glanced at his brother. Verne's cheeks were a mottled red and he kept clenching and unclenching his fists.

"No, don't worry about it. I can get a local train from here to Cardiff, then straight through to Paddington. I've already booked the ticket and they don't do refunds."