Ben didn’t know when he had fallen asleep. He remembered that he had kept digging until all his strength had been spent, and only his willpower had kept his arms moving mechanically. Every muscle was complaining as he forced himself back up onto his feet and rolled up his sleeves. Valentine and Nathaniel were sleeping too, sprawled over a mound of wet clay from their excavations. His brother looked filthier than a mudlark, Ben thought and smiled as he remembered those simpler days.

“Good morning, my boy,” Carter said cheerily as he hopped down from the vertical shaft that they had all been slaving on. “Welcome back to the land of the living.”

Ben couldn’t remember ever feeling so weary and yet Carter seemed almost rejuvenated, as if he found some special pleasure in adversity. Ben still didn’t have the measure of the man, but he recalled the feelings of joy that he had when the Watchers gave him the chance to rise above his circumstances, and he was too dog-tired to think of a more complicated explanation.

While the Watchers had been sleeping, Carter had kept working. Ben peered upwards into the tunnel and gave a low whistle – Carter had cut another three feet through the mud on his own.

“I’m impressed,” said Ben.

“Good,” said Carter, “I hate to be unappreciated.”

Then Ben’s nose twitched; he hardly dared to believe what he was smelling. “And now I’m really impressed.”

As well as scavenging oil lamps to light their work, Carter had also managed to find a hunk of ham, which was sizzling in a frying pan over a small paraffin stove.

“How?” said Ben, his stomach growling in anticipation.

“I’ve led expeditions across the glaciated plains of the Karakoram mountains, south of the great Tibetan plateau; I’ve crossed the endless dunes of the Kalahari desert; and I’ve never let my party go hungry. Although we did have to eat one of the native Sherpas once.” Carter saw the expression of horror rising on Ben’s face. “Sorry, Ben, just my sense of humour.”

Cannibalism, thought Ben. Ha bloody ha.

Still, the bacon did smell wonderful and the other boys were being lured back into wakefulness by its siren call.

“Dig in, lads,” said Carter, cutting off a thick slice for each of them.

Nathaniel grinned and juggled a hot piece of meat in his fingers before tearing off a chunk with his teeth. “Handsome,” he said appreciatively.

“A most welcome repast,” said Valentine, wrapping his own bacon in a handkerchief before gnawing at the corner.

The greasy bacon was such a treat that Ben found himself smiling even while his tongue was burning. “Ain’t life grand,” he said when he was finished, cuffing the fat off his lips appreciatively. “How much further do you reckon then, Professor?”

“By my calculations, we should break surface at daybreak, when with any luck the prisoners will be in the yard and the guards will be groggy,” said Carter. “There’s less than three feet to go.”

“So what are we waiting for?” said Ben, sprinting to the foot of the shaft and monkeying up inside. “We’ve got Watchers to rescue.”

With a crack like thunder, the whip lashed out. Lucy flinched as she felt its sting across her back but she didn’t make a sound – she refused to give her guard the satisfaction. Instead, Lucy kept the agony bottled up inside, sealed with a promise. Two days until the revolution, she thought as she regarded the Legionnaire with the whip. Just you wait until 1st May…

Lucy had been roused from sleep before sunrise. Along with Ghost and Mr. Moon and all the others who had incurred Mr. Sweet’s displeasure, she had been billeted in one of the wooden dormitories that had been erected in the detention camp. There were no beds to sleep on, no blankets to sleep beneath, just bare boards and the promise of death for anyone attempting to escape.

As a Watcher, escape had been on Lucy’s mind from the second that the Feathered Men had brought her and her friends to St. James’s Park. The detention camp was a desolate place. Like everything else that Mr. Sweet put his hand to, what once had been a place of beauty and joy was now home to misery and despair. A tall chain-link fence penned in the prisoners like cattle. Coils of barbed wire ran along both the top and foot of the fence. Anyone trying to get out that way would be cut to ribbons. As if that wasn’t enough, every sixty feet or so, manned watchtowers loomed over them. Lucy had been studying the movement of the guards, searching for a weakness, but she hadn’t found one. There were never less than six Legionnaires to each tower, ceaselessly scanning the camp with binoculars. There were rifles pointed in all directions, ready to halt any rescue attempt from the outside and quash any troublemakers inside.

“Eyes down!” the guard snarled again. “Keep walking.”

Grudgingly, Lucy obeyed and fell into step with the other prisoners.

Ghost was in front of her. Moon was behind her. All day long they were forced to march up and down in the rain, in ranks ten wide by ten long, like an old Roman Legion. The difference was that the Roman soldiers had been training to reach the peak of physical fitness, whereas the prisoners were being walked to death. There was no let-up, no allowance for tiredness or thirst or aching hunger. You marched through the rain or you tasted the lash of the whip.

Lucy marched.

Movement over by the main gate caught her attention. She squinted through the rain. “New arrivals?” she whispered.

“No,” said Moon, his two ears trumping her one eye. “You can hear from the sound of the suspension that the wagon is empty. This is something different; our old friend Mickelwhite has come calling with some of his brigade.”

“You’re sure?”

“Bedlam is wearing that boot with a squeak,” said Moon. “He rolls his shoulders as he walks to try and make himself look big and he always favours his left leg. As for Mickelwhite, well…” Moon allowed himself a chuckle. “Even in all this mud he still walks like he’s the lord of the manor and we’re all dirt beneath his feet. His buttocks are so clenched I’m surprised everyone can’t hear them squeaking too.”

The wagon was a Black Maria, the sort of reinforced wagon that the police used to round up suspects, with four black horses harnessed to the carriage. The prison gates closed behind it and were locked again. As Lucy watched, Mickelwhite and Bedlam joined the guards, the rain dripping from their hoods and for a minute they joked coarsely while they warmed their hands around a blazing brazier. Two Feathered Men were chained beside them, like the largest, most ferocious guard dogs she could imagine; vicious and slathering. Mickelwhite laughed again and then pointed a long finger in the direction of the prisoners.

“Can you make out what he’s saying?” whispered Lucy.

“Not all of it,” said Moon. “Something to do with a circus. Whatever it is, it sounds nasty. Mickelwhite has come here to round up some participants.”

The joking stopped and Mickelwhite marched over, shouting orders to the camp guards. “Line this miserable lot up!”

Instantly the guards began to bully the prisoners until they were standing in front of Mickelwhite, like troops awaiting inspection. Lucy, Ghost and Moon were three rows from the front. It wouldn’t be long before Mickelwhite spotted them.

Ghost took one look at Lucy’s flowing honey-gold hair and quickly whipped off his own scarf, wrapping it around her head. Lucy tied it tight and tucked the last few strands out of sight. Both their faces were brown with mud. It wouldn’t stand up to close inspection, but it might be enough…

Mickelwhite began to pace up and down in front of them, strutting like a cockerel.

You,” he addressed the prisoners, “have dared to defy our lord and master, King Oliver the Merciless! You have forfeited your right to citizenship in New London. But, His Majesty is prepared to offer you a chance at freedom.”

A murmur went up. This had to be some sort of trick; it couldn’t be true.

“I’m looking for volunteers for a…sporting event.”

“I don’t like this,” said Moon darkly.

“If any man or woman here can stand five rounds in the ring with Mr. Sweet’s champions, then they will receive his royal pardon and a second opportunity to take the Mark and start your life again.”

Lucy spat on the ground; she couldn’t stop herself. The Mark was the sign of allegiance to the Legion, a burning brand on the left palm which labelled you for ever as a servant of evil. That was not freedom as she understood it.

Even so, a young man standing in the row in front of Lucy cautiously raised his hand. “I’m in,” he called.

Lucy ground her teeth as she felt Mickelwhite’s arrogant gaze sweeping in her direction. She allowed her head to drop and hoped that it would be disguise enough. However, even as she lowered her chin to her chest, a movement behind Mickelwhite roused her interest.

The ground was moving.

A small spot, perhaps a dozen feet behind Mickelwhite, was writhing. Was it a mole?

Lucy couldn’t drag her eye away. The soil continued to stir and then a single lump of bedraggled turf rose ever-so-slightly into the air. Lucy blinked. Surely it couldn’t be…?

Ben!

She almost shouted out and her hand went to her mouth involuntarily. Ben had dug a tunnel. Lucy nudged Ghost and signalled with her eye but Ghost, ever vigilant, had already seen it.

Unfortunately so had some of the other prisoners.

A frisson ran through the ranks. One woman actually pointed in Ben’s direction. “That’s him, it’s got to be,” she said, so loudly she may as well be shouting.

“Shut it,” said Lucy through gritted teeth. “You’ll give the whole game away.”

Moon had picked up enough from the whispers all around him. “Ben’s come for us,” he said. “Good lad.”

A man in the front row stepped forwards, edging himself towards the hole. Then a second followed and a third.

Mickelwhite clapped his hands together in malicious glee, assuming that they were volunteers for his circus. But when more and more began to shuffle in his direction, his expression changed.

“Halt! I command you!”

“We go now,” said Moon, his voice full of steel. “If we don’t, it’ll be too late.”

With that, he put his hand in the small of Lucy’s back and propelled her towards the tunnel, while he lowered his own head and barrelled towards Mickelwhite.

“Oi!” shouted Moon. “You, with the silver spoon in yer gob. Yes, you! Mickelwhite! You flap-mouthed whey-face! I’m talkin’ to you!”

The Old Watcher shouldered through the crowd and threw himself at Mickelwhite before the Legionnaire could react.

“Ben Kingdom sends his love,” said Moon, grabbing the captain by the shoulders and then butting him in the face.

“You’ve broken my nose, you old codpiece,” Mickelwhite cursed as he dropped to the ground. The guards in the watchtowers noticed the commotion and immediately shots began to ring out.

Lucy ran towards the tunnel for all she was worth, but others made it there before her, diving for the hole and half-falling, half-climbing out of sight.

It was a stampede.

Lucy had once seen a bull break loose in Smithfield market. Before the beast could be brought under control, seven people had been hospitalized and two were dead. But the animal hadn’t caught anyone on his horns; the victims had all been crushed to death by other people. Lucy remembered the wave of terror that had spread through the market, the screams as people ran in every direction, falling over themselves in their panic to get away, trampling friends and family underfoot. That was what was happening in the camp.

Lucy saw men and women slipping in the mud as they dashed towards their only chance of freedom. The two Feathered Men had been let off their chains and one snatched up an escapee, shaking the man vigorously until the snapping of bones ended his escape attempt. Moon was surrounded by Legionnaires, lashing at him with their whips. Ghost was nowhere to be seen at all.

A stray bullet zinged past Lucy’s ear. From the tower, Legionnaires were alternately firing rounds into the air and peppering the mud with shots in an attempt to force the prisoners back. Other guards ran across the yard, knocking prisoners down with their rifle butts, pushing them away from the tunnel and back towards their huts. Lucy caught more horrific glimpses of the Feathered Men’s ferocity, driving the detainees back against the wire fence. Red splashes in the rain.

From one of the watchtowers, the dreadful wail of a siren cut through the air, summoning more of the fallen angels from their roosts, more Legionnaires to quash the escape. Another bullet hit the mud just in front of Lucy’s feet. It was now or never.

She poured every last reserve of strength into a final push. Legionnaires were advancing from every direction and a hail of bullets and crossbow bolts sliced across her path. Incredibly she came through unscathed and threw herself into a dive, sliding across the mud on her belly until she was peering down the shaft.

Mud-slick bodies were scrambling down ahead of her but there was no mistaking the figure at the foot of the shaft, helping them on their way.

“Ben!”

She lowered herself over the edge. She was so relieved to see Ben that she didn’t notice the Feathered Man swooping down until its beak was snapping at her face.

Lucy gasped in shock – then gasped again as a crossbow bolt pierced the creature’s neck. Hurriedly she continued her descent, her feet scrabbling for purchase in spite of her Watcher skyboots. Just as her head dropped below the surface she caught sight of Ghost running after her, his stolen crossbow still raised.

It was a tight squeeze in the shaft. Lucy braced herself with her hands and feet, but the supporting props were slick with rain and she flinched as first her foot slipped off the wall, then a plank came away in her hand with a squelching sound.

Her heart was racing by the time she reached the bottom and almost fell into Ben’s arms.

“I thought for a moment you were going to stand me up,” said Ben.

Lucy smiled. “I’m washing my hair tonight,” she said.

Claw Carter was waiting at the end of the passageway with Nathaniel, their hands outstretched to the fleeing prisoners who slithered and stumbled towards them. Ben knew that Valentine had bravely gone on ahead to lead the escapees to safety – hopefully they’d all meet up again at today’s rendezvous. Ben was thrilled that so many had got out of the camp, but he knew that time was running out and he searched every face for Ghost and Mr. Moon.

Looking up through the shaft, Ben caught a fleeting glimpse of Ghost’s shaven head peering down. Ben’s hopes soared – only to be dashed again as a Legionnaire grabbed Ghost by the shoulders and yanked him away. Ben made to climb up after him but he halted as a rumble filled the underground corridor. The whole tunnel began to judder and a fine rain of dirt began to fall…

“Run!” shouted Carter. “Ben. Lucy. RUN!”

Lucy’s ears rang as the props began to snap away from the sides of the shaft with the explosive bangs of Chinese firecrackers. Ben grabbed her hand and began to wrench her away from the danger but the roaring darkness was just too quick. With a hideous, hungry slurp the mudslide filled the shaft, winking out the light. Tons of slick soil collapsed in on top of them. Lucy clung to Ben’s hand for dear life, but her fingers were not strong enough and as the falling earth smashed her to the ground she lost grip.

Mud filled Lucy’s mouth. Her ears. Her nostrils.

Help! thought Lucy.

And then the mud stopped her thinking anything at all.