“This is the police. Return to your homes. Stay inside and bar your doors and windows. Do not venture onto the streets. A state of emergency has been declared. Return to your homes. This is the police. Return to your homes. Remain inside.”

The mammoth flying machine slowly slid away over the rooftops. As it passed, ash-laden smoke rolled back over Burton and his colleagues.

A horse bolted past, trailing the broken shafts of a wagon behind it.

Somewhere nearby, glass smashed and rained onto the pavement.

Incoherent shouts echoed from the near and far distance.

Cautiously, they moved on.

Ahead, a male voice pleaded: “Help me! Oh, sweet Lord, help me! No! Please! Though I walk in the valley of death I shall-”

It was cut off.

A broken walking stick came whirling out of the miasma and clattered onto the cobbles inches from Burton's feet.

Moments later, through the gloom, they saw the other half of it. One end was held in the hand of a snarling street pedlar. The other end-the broken end-had been thrust up into the base of an elderly clergyman's chin and was projecting from the top of his skull. The pedlar was holding his victim upright but released him as he saw the trio approaching. The dead man crumpled to the pavement. His murderer laughed. Froth sprayed from his mouth. He wiped his bloodied hand on his thigh.

Without hesitation, Burton shot cactus spines into the pedlar's neck and winced at the sound the man's skull made as it hit the road.

“We should proceed with greater haste,” he advised Palmerston's men. “Can you manage?”

“Yes, Captain,” Hare replied. “Though Mr. Burke seems to be uncon- Look out!”

Burton gasped and stepped back as a wraith materialised right in front of him. He saw the figure clearly. It was dressed in a long frock coat, wore a top hat, and its mouth was hidden behind a soup-strainer mustache. Then it dissolved and blew away, nothing but a ribbon of dirty particles.

“What are those things?” Hare whispered.

“I don't know, but each time I see one it appears a little more solid, more opaque. I think they're gaining in strength, and they're inciting this violence.”

They pressed on and reached Saint George's Circus. A man ran out of a shop, stopped in front of them, and raised an antiquated blunderbuss.

“Die for Tichborne, you posh sods!” he shouted. He pulled the trigger and the weapon exploded in his face, blowing off his right ear.

“Christ!” he screamed. “My bloody head!”

Burton shot him and the man crumpled.

The rumble of approaching wheels came out of the smoke.

“Let that be an empty cab!” Burton pleaded.

It was.

A steam-horse erupted from the fumes, pelting along at full speed, its crankshafts clanking. It was dragging behind it an old-fashioned landau, engulfed in flames. The vehicle careened past them, bounced onto the pavement, and ran smack into the front of a tavern. Glass burst noisily and an angry clamour of voices came from within the building. The vehicle's boiler detonated, hot metal flying in all directions. The front of the building collapsed into the street, sending bricks, glass, and masonry spinning into the air.

Gregory Hare yelled in pain.

Burton turned and saw that a chunk of metal had embedded itself in his colleague's left arm. He slipped under the semiconscious Burke's shoulder to keep him upright and gave a steadying hand to the other man.

“Oof!” Hare grunted. “This isn't good! Ouch! Ouch! Not good at all, Captain!”

The king's agent looked at the wound.

“Wait,” he snapped.

He lowered the two men to the ground then shrugged out of his jacket, dropped it, gripped the sleeve of his shirt, and ripped it off.

“How many tourniquets am I to tie today, hey, Hare? Must you and Burke do everything together? You both have wounds in exactly the same blessed place!”

“I apologise, sir,” Hare groaned. “A terrible inconvenience. Is it serious?”

“Three men, two out of action, one weapon between them, in the midst of a riot? Yes, I should judge that to be fairly serious. As for the wound, it would be as severe as Mr. Burke's were it not for the fact that your biceps are the size of thigh muscles. The bone is intact.”

“As I say, sir, I'm terribly sorry.”

“Don't be a fool,” Burton growled, tugging the tourniquet tight. “You hardly leaped into the path of that projectile.”

In the distance, the police announced: “Get off the streets. Remain inside.”

Tongues of flame licked from the ruined tavern. Screams came from within.

Burton retrieved his jacket and put it back on. “Mr. Burke is out cold. Stay with him. Hold this.” He pushed the cactus gun into Hare's hand. “I'll be back in a jiffy.”

He dived into the murk. Something had caught his eye moments ago. It had possibilities.

“We have to keep moving, Captain!” Hare called after him.

Burton ran back the way they'd come until he reached the edge of the square. He peered to his right, through the swirling haze.

It was still there.

He returned to Burke and Hare.

“There's an abandoned omnipede,” he reported, taking back the pistol. “I suggest we hijack the blighter. It'll get us over Waterloo Bridge in no time.”

“You can drive the contraption?” Hare asked.

“I can try. I don't think the controls are much different from those on a rotorchair. Come on.”

He helped Hare with Burke, dragging him along until they reached the giant mechanised millipede. It was slumped across the road, empty but for the driver, whose corpse hung over the edge of the control seat.

“Looks like he was bludgeoned,” Hare muttered.

They hauled Burke up the steps in the side of the vehicle's carapace and laid him on a bench. He stirred and moaned.

“Help me to shift the driver,” Burton said. “Try not to use your injured arm-I don't want you bleeding any more than you already are.”

“Me neither, Sir Richard.”

They descended and moved to what used to be the head of the gigantic insect. As they dragged the dead body down and across to the side of the road, Hare noted that there weren't many people about. “It seems like a wave of rioters has come and gone through this part of town,” he ruminated. “I wonder where they are now? Do you think they're still at it, Captain?”

“From the various cries and screams we're hearing, it appears that passions are still running high,” Burton replied. “But whether the riot is dying down or has just moved past this district remains to be seen. There were certainly a fair few unfortunates in that tavern when the landau hit it.”

He suddenly pointed the pistol at the other man and pressed the trigger. With a soft phut! seven spines flew past Hare's ear and embedded themselves in the throat of the woman who'd loomed out of the smoke behind him. The length of pipe she held poised to crack down onto his head fell from numb fingers and clanged onto the road. She dropped on top of it.

“Much obliged,” said Hare.

“Take the cactus gun again. I'll drive. You shoot.”

Hare grasped the proffered weapon and clambered back onto the omnipede. He stood by the bench upon which Burke lay and braced himself against the canopy, clamping his injured arm against his side, holding the spine-shooter ready.

Burton slipped into the driver's seat and examined the controls. A gauge indicated that the furnace was still burning and another that boiler pressure was high. He settled his feet onto a plate which operated in the same way as the one in his rotorchair: press it forward with the toes to accelerate and backward with the heels to slow and brake. There were two levers to facilitate steering.

“Simple enough,” he breathed. “Let's be off.”

He pushed gently on the footplate. The insect shuddered and rattled, steam whistling from the vents between its many legs. It jerked ahead, stopped, the engines spluttered, snarled, and the vehicle began to rumble forward.