“We need to talk, Ben,” said Nathaniel Kingdom.

For the last hour or so, Claw Carter had been guiding their small party. A secret trapdoor in the basement of Madame Tussaud’s opened onto a stretch of cobwebbed tunnel, which in turn had connected them to the main hub of the abandoned Under. By the swaying light of his lantern, the professor’s face was intermittently flung into stark relief. They could both see the broad smile on the man’s long, lean face, the occasional flash of teeth in the darkness. Somewhat disconcertingly, Carter appeared to be thoroughly enjoying himself.

“I don’t trust him,” whispered Nathaniel, when Carter and Valentine seemed far enough away. “He’s even humming to himself! What sort of man hums when he’s trying to break into a heavily armed detention camp?”

Ben paused and heard Carter’s tune for the first time. It did sound very jolly, all things considered. “We need him,” said Ben. “How else could we navigate through the Under?”

Nathaniel shook his head. “Stop being so naive, will you? We have no idea where he is taking us. He could be leading us into a trap for all we know.”

“I trust him,” said Ben flatly.

“You’ve always thought the sun shines out of his backside, Ben,” said Nathaniel angrily. “When we were just nobodies, back on Old Gravel Lane, you were always running off to see your precious professor. It made Pa and I feel like we weren’t anything to you—”

“Don’t bring Pa into this,” snapped Ben.

Nathaniel had jabbed a deep wound and Ben felt the urge to hurt his brother back. What Ben wanted to say was that Nathaniel had always had the lion’s share of their father’s affections. That Ben had felt lonely in their family of three, always the odd one out. Was it any wonder that he had enjoyed speaking to Carter? At least the professor had treated him as if he was worth listening to. Instead Ben clenched his teeth and kept the words inside; if Mother Shepherd had taught him anything it was to think before he spoke. Life and death is in the tongue, Ben. Every man speaks his own destiny, for good or for ill.

“Carter is my friend,” said Ben; it was the only explanation that he could give.

“Exactly,” retorted Nathaniel. “The man who tried to kill our father is your friend. Think about it.” Nathaniel drew his finger across his neck, and Ben chilled at the memory of Carter’s claw making that same journey across Jonas Kingdom’s throat. “You’re some sort of chosen one now,” Nathaniel continued, “the one the Watchers have been waiting for—”

“You’re a Watcher, too,” said Ben.

“Yes,” said Nathaniel, “for about four months, the same as you. That hardly makes us experts, does it? Anyway, as I was trying to say, I can go along with the idea of you being a hero – you’re my brother, after all…” Ben was relieved to see the spark of warmth returning. “I can even cope with Carter being forgiven, which is sort of what the Watchers are all about – everyone deserves a second chance an’ all that. But what I’m struggling with, what we’re all struggling with, is how you can make the sworn enemy of the Watchers your right-hand man.”

Ben could see that Nathaniel was trembling slightly. It was clear that he had been bottling these feelings up for some time. Although he was younger than Nathaniel, Ben knew that it was up to him to be the bigger man – that was part of what being the Hand was about. He put his arms around Nathaniel, and although his brother resisted at first, they soon melted into a hug.

“Pa’s somewhere outside the Wall,” said Nathaniel softly. “Josiah’s dead, Mother Shepherd’s dead, Lucy’s a prisoner, Mr. Moon’s a prisoner, Ghost’s a prisoner and who are we left with? Carter and Valentine, both sworn members of the Legion until recently. Truth is, Ben, I’m frightened. Claw Carter frightens me.”

“I know,” said Ben. “I’ve been flung into the role of leader and I can tell you I spend half my time feeling scared. But if being a Watcher means anything, I think it means that we have to be brave, to take a chance…a leap of faith. And sometimes the biggest leap is to believe that each of us can be more than anyone else imagines. Look at me, Nathaniel. Six months ago I was nothing, just another mudlark, up to his neck in muck and trouble, with no future to look forward to except working too hard and probably dying young. And now I’m the Hand of Heaven, so they say.”

Nathaniel listened.

“The Watchers didn’t see a street rat when they looked at me,” said Ben, “they saw something more. That’s what the Watchers do, Nathaniel – they look for the best in people’s hearts…and they find it.”

“Well, it was buried pretty bloomin’ deep in Carter,” said Nathaniel.

“You’re not wrong,” Ben laughed.

“DON’T MOVE, MOLLY!”

Jonas Kingdom hadn’t meant to shout but Molly had to understand the danger she was in.

He approached the girl carefully, picking a path towards her through the rubble. His eyes flicked between the girl and the ground before his feet. They had all seen the explosions when escapees had blundered onto a landmine in Mr. Sweet’s death zone. One wrong foot…

Molly was quaking now. She looked so vulnerable to Jonas; a frightened little waif, standing on a bomb in the rain. She had the blasted dog cradled in her arms, but Jonas was grateful for it – the three-legged mutt gave the girl some comfort, breathing against her face in short, hot bursts and licking her affectionately.

Jonas reached Molly’s side. “You’re going to be alright,” he said. “I promise you that, but you have to promise me something too.”

Molly nodded, her eyes wide with fear.

“You have to promise to stand as still as a statue.”

Molly nodded again.

“Good girl,” said Jonas and he crouched down to inspect the situation. In truth Jonas had never seen a land mine before and he had no idea how to disarm one, although he did have a rough knowledge of how the monstrous things worked. You stood on one and that set the primer, took your foot off again and BOOM.

“You there!” A voice called out to them from behind the army barricades. “Get in, man, you’re making yourselves open targets!”

Jonas turned and saw a British officer beckoning to them urgently.

“We can’t, sir,” Jonas explained, gesturing to Molly’s predicament with a sideways tip of his head.

“Oh, I see,” said the officer calmly. “Stay where you are, the pair of you, I’m coming over.”

The soldier walked briskly over and joined Jonas in an examination of the landmine. “Beastly things,” he muttered. “A coward’s weapon.”

The soldier kneeled and drew a screwdriver from his pocket, keeping up a running commentary of his actions. “I’ve dealt with a few of the blighters before,” he said, smoothing his hand over the metal surface of the device until he found a raised panel fixed with four screws. He set to work quickly and efficiently, removing the plate so that he could get to the deadly workings inside. “These are an especially nasty sort. Sweet’s thugs have added a clockwork timer…” The man squinted into the dim interior and fished in his pocket for a pair of wire-cutters. “The trick is…” he said, gingerly reaching inside, “to remember the right order when cutting the wires…”

Jonas was frozen to the spot. He had been in some tight corners himself but he had to admire this man’s steely calm. Probably only a few years older than Jonas, the officer looked like a military man from a long line of military men; clear eyes, strong mouth, neatly brushed moustache. The British Empire had been built on men like him.

“Red before yellow kills a fellow,” said the soldier with conviction. “So, yellow it is.” With that, the soldier confidently cut the first wire in two, although Jonas noticed a flicker of relief cross his face when they weren’t all blown to kingdom come. Satisfied that they were in the clear, the soldier even gave a little whistle as he cut the red wire.

In a gentlemanly fashion, the officer rose to his feet and extended his hand for Molly to take. “This way, if you please,” he said, like a prince from a fairy tale.

“This is Clover,” said Molly, holding up the toad-faced bulldog and waving him in front of the soldier. “He wants to be your friend.”

“And what’s your name, young lady?” asked the officer.

“I’m Molly,” she said, beaming.

Regardless of the downpour, the soldier unbuttoned his greatcoat and swept it round Molly’s shoulders. She almost disappeared from sight within its folds.

“Right,” he said briskly, “let’s get out of this rain.” He indicated a green canvas tent a little way back from the front line of ruined houses. “Temporary HQ. Not much to look at but there’s a paraffin stove inside and I can promise you both a mug of tea.”

“Will there be biscuits?” asked Molly.

“For you, young lady, there just might be,” said the soldier with a smile.

Gratefully they walked over and stepped inside, welcomed by a wave of warm air. Molly put Clover down and ran straight for the stove, extending her hands towards it.

The officer put his own hand out for Jonas to shake. “I saw you piloting that airship. Very brave thing that, saved a lot of people.”

“There’s thousands more on the other side of that Wall,” said Jonas. “They all need saving.”

“We know,” the soldier sighed. “Sweet’s got us trussed up like turkeys at Christmas, damn his eyes. We daren’t risk Her Majesty’s life. But give me half a chance…” He slammed his fist into his palm and rubbed his knuckles. “At least the Prime Minister made it out, although he’s a shadow of his former self. Seems that he was the victim of some sort of terrible mental torture.”

The soldier looked weary. “Sorry,” he said, “where are my manners? I’m Carnehan,” he said smartly. “Brigadier Daniel Carnehan, commanding officer 1st Battalion Coldstream Guards.”

“Jonas Kingdom, at your service.”

Carnehan’s face lit up. “Not related to Ben Kingdom, by any chance?”

“My boy,” said Jonas.

“Very pleased to meet you, sir,” said Carnehan. “All we ever hear from the escapees are extravagant tales about this Ben Kingdom and the ‘Watchers’. You appear to have a very remarkable son.”

Jonas nodded. “That’s one way of putting it.”

“And is our plucky young lady your girl?”

“I’m more of her guardian, actually,” Jonas explained. “I knew her father…it’s a sad story.”

“Aren’t they all?” said the brigadier thoughtfully. “A child should have a family. My wife and I always wanted children but…” Carnehan’s eyes became distant for a moment before he returned to the matter in hand. He pulled two chairs closer to the stove.

“I have to ask you,” said Carnehan, beckoning Jonas to sit. “Is everything set for Revolution Day?”

For the next half an hour, the Kingdom brothers followed Valentine and Claw Carter deeper into the Under. It was very different to the first time that Ben had descended into the Legion’s secret world beneath the London streets. When the Legion had been in hiding, the Under had been a bustling community; albeit a community of scoundrels, lowlifes and rogues. Now, walking behind Carter, Ben had the feeling that he was actually on one of the professor’s archaeological expeditions, visiting the decaying remnants of a lost society.

The Legion had no more need to skulk in the shadows. When Sweet swept into power, there was a mass exodus from the Under, as its denizens snatched whatever property on the surface took their fancy. Well-to-do families in Mayfair found themselves slung out to live in the gutter, like the beggars they used to despise. Rumour had it that the Savoy had become home to the most notorious murderers.

The abandoned Under was a ghostly place, Ben thought, full of shadows and dark memories. Cups still sat on tables, half-eaten food rotted on plates, chairs were overturned where their occupiers had stood in a hurry and never returned. And yet Ben had the eerie sensation that they were not alone.

They only had their lamps to guide them and Ben couldn’t shake the feeling that when their feeble light passed by, the shadows were moving behind them. More than once they all stopped, listening for footsteps that were not their own. They weren’t helped by the drip-drip-drip of falling water, echoing through the tunnels. There was almost as much rain down here as there was up top, thought Ben. It was leaking through the brickwork, finding every weakness in the mortar. In some places it was running freely down the walls, so that they were walking through icy puddles. Ben was glad that they didn’t have to venture into the lower levels; all this water had to be going somewhere.

The other noise that surrounded them was the shrill squeaking of the rats. Thousands of them, Ben reckoned, all happily making the Under into their own kingdom. Everywhere Ben’s eyes fell, he spotted their bloated bodies and naked pink tails. Scrabbling up bedsheets. Scurrying across tables. Scampering over furniture. Chewing everything, defecating everywhere; their huge black eyes always searching for more.

In one of the deserted dormitories Ben saw a mattress which appeared to be undulating. It took a moment for him to realize that it was one solid mass of rodents. He pulled the door shut and walked swiftly by.

“This is it,” Valentine declared, swinging his lantern up towards the ceiling. “We’re directly beneath St. James’s Park.”

Ben was glad of Valentine’s remarkable knowledge of the labyrinthine Under. And he liked the irony that the boy’s distant ancestor, Sir Alasdair Valentine, was the original architect of the Legion’s home back in the days of Henry VIII and now the Watchers were using that knowledge against them. Yes, despite Valentine’s background, Ben trusted him. When Ben had met him, the boy had been at death’s door, riddled with consumption, before the power of the Hand had restored him to health. The first thing Valentine did with his new strength was get as far away from the Legion as he could; that was good enough for Ben.

Carter tapped on the ceiling with the tip of his quarterstaff.

“Your friends are about fifteen feet that way,” he said.

Your friends, Ben noted. Not ours.

“We need to start gathering as much wood as we can find. We’ll have to shore up the sides of the tunnel as we dig,” said Carter. “I suggest we split up, we’ll cover more ground that way. Nathaniel, Valentine, you’re on wood duty. Straight flat lengths are what we’re after. Ben, I want you to come with me.”

“Why?” said Ben, feeling the control of this rescue mission slipping from his hands.

“Two reasons, actually. Firstly, because I need you to help me collect some excavating equipment. There’s a tool locker on this level. We can hardly dig with our bare hands, can we? And secondly” – he grinned that grin again – “I don’t think some of the other members of your little gang want to be left alone with me.” This with a pointed look at Nathaniel. “I don’t blame them,” said Carter, sounding very reasonable about it. “If the positions were reversed, I wouldn’t trust me either.”

Ben fell into step beside Carter and they set off together, his brother and Valentine heading in the opposite direction.

“Work on the tunnels never really stopped,” Carter explained. “If I’m right, and I normally am, we should find a store with some picks, shovels and other basic equipment just round this corner.”

Carter brought them to a wooden door and promptly chopped the lock out with his claw. “Open sesame,” he said.

As Ben stepped inside, the crunch of a footstep behind them alerted him to another presence skulking in the darkness. Then, before he could react, Carter shoved Ben forward savagely. Ben staggered blindly into the dark confines of the tool store, falling to his knees as he tripped. He was back on his feet in an instant, but it was too late.

Carter slammed the door shut, holding it closed with his full body weight.

Ben hammered on the wood. “Let me out!”

There was no reply.

Desperately, Ben pounded on the wood again.

“Professor!”

The only answer was silence.

All of Nathaniel’s warnings about Carter screamed in Ben’s mind.

How can I have been so wrong?