The long journey back to New London was tense and awkward for all of them. Even Reginald Fox seemed apologetic about what he'd done. When he did speak, it was to try to justify his actions, explaining to a silent room what they knew about the failure of the Mars colony and all the reasons he had for believing that a second attempt to colonise the red planet would be no more successful than the first. Cheval and Windsor pointedly ignored him, acknowledging his existence only when his gunshot wound needed treatment.

     Windsor's frostbitten back began to scab over after a day or two, and the pain receded enough to allow him to wear a coverall, although he was careful when sitting down, lowering himself into the chair slowly and then keeping as still as possible to avoid rubbing the damaged skin. The doctor who examined him over the video link said he thought that the damage would heal without the need for skin grafts, although he would carry the scars for the rest of his life. Cheval's leg also looked as though it would heal without him being handicapped by it. Within a few months he would have recovered completely with only a scar of his own to remember it by.

     When they were half way back to the city they were met by another rover to take Reginald Fox off their hands. The authorities seemed to think that, even though he was virtually incapable of rising from his bed, he might still cause some mischief with both police officers injured. Windsor and Cheval were very happy to see the back of him, and so didn't bother to point out that, with his mission accomplished, he no longer had any reason to cause mischief.

     Their rover came to a halt somewhere in the middle of what had once been France and the other rover parked behind their own, back to back. The two rovers, under the control of their autopilots, then reversed slowly together until the two airlocks mated together forming a solid connection. Three burly police officers then came across with a gurney. They placed Fox on it, none too gently, then carried him back through the airlocks after which the two rovers continued on their way to New London, side by side.

     Andrew declined every invitation to speak to reporters over a video link. The only people he wanted to talk to were his wife and children, who were also being pestered by reporters. "They keep knocking on the door," said Susan, frowning at him from the screen of his tablet. "Wanting to know what we think of what you did. Whether we think you could have done more."

     "Next time they can try," replied Andrew bitterly. "See if they can do any better."

     "You promised me you wouldn't take any risks!" Susan scolded him. "You were only supposed to drive the rover. The policemen were supposed to do all the dangerous stuff."

     "Believe me, if someone else could have done it, I would have been delighted to let them."

     "When I saw the footage of you jumping from one rover to the other..."

     "What, wait!" interrupted Andrew, holding his hands up in front of the tablet screen. "You saw me jump?"

     "Everyone did. Someone leaked the footage to the press and it's been all over the news. The children just stared like they couldn't believe it. I mean, you're their dad. You make them tidy their room, you make sure they do their homework, and all of a sudden you're leaping from one rover to another on top of an active volcano like some kind of action hero. I almost had a heart attack!"

     Andrew grinned. "So does that mean I'm the coolest dad ever now?"

     Susan dropped her eyes. "If you'd succeeded, maybe. As it is, the children are getting a hard time from the other kids at school."

     Andrew glared. "I'll talk to the teachers. I won't have my children bullied."

     "I already have, but children don't just meet in school. And they've been accosted by reporters while going to and from the youth clubs, the swimming pool, the gym..."

     "I'll be back there tomorrow and all this will stop, I promise. If they want to harass someone they can harass me. I'll give an interview. Put the whole thing to bed once and for all."

     "I think that'll just make things worse. We're all hoping this'll all just blow over once another big story comes along. Giving an interview would just be stoking the fire."

     Andrew nodded, glad for the excuse not to have to go through with it. The idea of giving an interview terrified him. "It'll all be okay, I promise," he said. "I'm sorry this is happening to you. To all of you." He gave a heavy sigh. "I suppose this is who I am now. This is who I'll always be. The man who failed to stop Fox. The man whose failure condemned the human race to always be trapped on this planet..."

     "Andrew, stop! There were three policemen in that rover with you. It was supposed to be their job to stop Reginald Fox, not yours, and one of them betrayed you. Fox and Kartoshka are responsible for stopping The Return, not you. And that guy on rover seventeen. Even the reporters know that, you can tell from the questions they ask. They just want to stir things up, to make more headlines. You can't blame yourself. Don't let the reporters make you think that it's all your fault."

     Andrew nodded, and gradually he began to smile again. "But just imagine if I had managed to stop the rover," he said. "I would have been a legend! Parades, speeches, a knighthood, if there were still knighthoods. Interviews, a book deal..." His smile faded. "And if the second Mars colony failed, the last generation of mankind might have remembered me for an entirely different reason." He immediately regretted that last sentence as he remembered that the video call was almost certainly being monitored by the New London authorities. "Not that it would have failed, of course. I guess we'll never know now."

     "I guess not. The children want to talk to you. Shall I let them in now?"

     "Yes, please do."

     Susan got up out of her chair and disappeared from the screen, and a moment later David, James and Jasmine were there, crowding excitedly together as they all tried to speak at once.

☆☆☆

     "I suppose they'll be finishing that now," said Windsor the next day, sitting carefully in the co-pilot's chair and looking out the window.

     Andrew turned his head to see what the other man was looking at. A circular wall of steel and concrete a mile across. Up to fifty metres high in places, lower in others where it had been left uncompleted as the promise of The Return had loomed closer. It was going to have been topped by a dome and then filled with breathable air and the floor covered with soil in which trees and grass would have grown and animals allowed to roam freely. Animals grown in artificial wombs from DNA taken from frozen corpses buried in the ice. The first domed garden. The first of many, others of which would have been bigger once they had worked out the technical glitches from building the first. A place where people could walk under a blue sky and a simulated sun almost identical to the real thing. A return to how life used to be before The Freeze.

     "Probably," Andrew agreed. "They'll probably make a big song and dance about it to make people forget that the real sun has been lost forever. I wonder how long it'll be before the rich and powerful make their homes in those domes while the rest of us have to stay underground."

     "They wouldn't dare," the Constable replied. "They wouldn't dare risk a public uprising like the one that destroyed New Beijing. Our survival depends on everyone doing their job. Tending the algae farms, manning the geothermal plants. Tending the atmosphere recyclers. If those people stop doing their jobs because they're too busy fighting the ruling classes, we all die. The Council knows that their own survival depends on keeping everyone happy. They wouldn't be stupid enough to try the kind of oppression and power grabbing they used to do back in the old days."

     "We hope," said Andrew doubtfully.

     "They haven't for two hundred years. Not in this city anyway. The rich and powerful live better than the rest of us, of course, but they don't rub our faces in it. Their mansions and palaces are underground where all we can see is the front door. If they built a palace in a domed garden like that, though, where everyone could see it, people wouldn't stand for it. They know that, which is why they won't do it."

     "I hope you're right," Andrew replied. "I can't help but wonder, though, whether the temptation will eventually become just too great."

     "If it ever does, we'll need to remind them that there used to be twelve underground cities," said Windsor. "Twelve, and New London is the only one left. They weren't all destroyed by rampaging mobs and the Hoder earthquakes. New Beijing and New Richmond were destroyed from within by civil unrest. Their rulers thought they could rule like Kings. They thought that the very fragility of their existence would protect them because the workers would never dare rise up."

     He fell silent as the Dartmoor Memorial came into sight ahead of them. The polished slab of granite engraved with words picked out in gold and with a light shining on it so that it could be clearly seen even in the dim light of the distant sun. 'Beneath this ice lie those who gave their lives so that humanity would endure. Let those who come after see to it that their names are not forgotten.'

     The two men said nothing for the next few minutes as the rover drove across the site, now buried beneath the ice. The site where thousands of men and women had died holding back hundreds of thousands of people desperate for the safety of the underground city. There was no actual rule that demanded it, but a tradition had arisen, seemingly of its own accord, that one did not break the respectful silence while crossing the site of the Battle of Dartmoor, and after what they'd seen during the pursuit of Reginald Fox's rover the moment had a power and significance for both Andrew and Windsor that it never had before.

     Half an hour later, as they left the the battlefield, they finally saw the city's down ramp ahead of them and Windsor opened a channel to the city. "New London traffic control," he said. "This is hab-rover nine, requesting entry through the blast doors."

     "Roger, rover nine," a voice replied from the speakers. "Your identity has been confirmed. Opening doors. Welcome back."

     "Stupid security checks," muttered Andrew to himself. "There's nobody else anywhere on the whole planet. Why do we have to prove who we are?"

     "It only takes a second to read the transponder," said Cheval from behind them. Andrew looked around to see him standing in the doorway. "We don't even have to slow down. I suppose someone thought it worthwhile to eliminate even a one in a million chance that someone else might have somehow survived somewhere. There were hundreds of private refuges, after all, along with the twelve official underground cities. Can we be sure they all failed?"

     "After what we've seen?" said Andrew. "Yes, I think we can be sure."

     "Well, the city authorities haven't seen what we've seen. All they know is that they're safe, warm and comfortable. Maybe someone else is as well. Some twenty first century billionaire who built a secret little place for himself and a small bunch of cronies. Hidden so it'd be safe from the mobs."

     "If there was, they'd have emerged when we did," said Andrew. "They'd have heard our radio chatter. They'd have seen the satellites and the space station. All the spaceships parked alongside it, ready for The Return. They'd have made contact. Introduced themselves."

     "The job of the security guys is to be ready for any threat," the Sergeant told him, "and they take that responsibility very seriously. Speaking for myself, I'm very glad that they do."

     "Yes, of course," said Andrew, returning his attention to the road ahead.

     The ground here, so close to the city, had once been a smooth expanse of ice as perfect as the surface of a skating rink, just like much of the rest of the planet. Now, though, the passage of dozens of rovers over the past twenty years had left it broken up into an icy gravel to a depth of fifty centimetres. One day, Andrew mused, they would have to build some kind of road network to and from the city, perhaps used by smooth wheeled vehicles with the cleat wheeled rovers relegated to driving over virgin ice only.

     The down ramp itself was coated with nitrogen ice to give the rover a firm grip as it descended the gently sloping tunnel towards the blast doors. As the rover passed, nitrogen vapour was sprayed into the tunnel to condense onto the floor and hold the nitrogen gravel in place and keep it from all sliding down to the lowest point. Restoring the surface ready for the next rover to pass that way, either upwards or downwards.

     Lights illuminated the words 'New London' above the massive steel doors. They opened as they drew close with a rumbling vibration that they felt transmitted through the ground and into the rover by way of the wheels. Those doors had closed two hundred years before, when the last of the city's first inhabitants had passed through, and they had survived a relentless bombardment from the mobs left on the surface, those that had made it past the valiant defenders. They hadn't opened again until twenty years before when the survivors had dug themselves out, to find all trace of the conflict buried under ten metres of nitrogen ice.

     Andrew stared at the thickness of the doors as they approached and marvelled at the power of the engines that could move such a mass of solid steel. The outer surface was pockmarked where missiles and explosives had been used against it, but Andrew's eyes were drawn, as always, to some words that had been engraved near the bottom by a man with an oxy-acetylene torch. One of the last to succumb to The Freeze. The words read 'Damn you all to Hell'. It would have been easy to remove those words, but the authorities had chosen to leave them and Andrew was glad they had. Those left to die on the surface also deserved to be remembered.

     Then they were through and the doors were closing behind them. The road continued to slope downwards until they were more than a hundred metres underground where they came to the garage level, a wide, open space the size of a car park. There were nearly a dozen other rovers of various designs already there. Hab-rovers like their own, cargo rover, buses, various pieces of mobile construction equipment. Even a couple of ancient IceRunners, showing their age but still operational after twenty years. All parked with their back to the circular outer wall where their airlocks connected to the sixty docking spaces the chamber contained.

     The Birch family's rover did a U-turn in the chamber's large central area, then reversed towards a vacant docking space. There was a clunk as the two airlocks connected, and then the rover's atomic generator powered down and darkness fell in the cockpit as all the monitors and instrument panels turned off.