At the end of the Mall he passed Buckingham Palace and turned right into Green Park. Rather than walk along Constitution Hill itself, he preferred to pace along on the grass, thus positioning himself behind any crowd that might gather along the queen's route. In his experience, the troublemakers usually hid at the back, where they could more easily take to their heels should anyone object to their catcalls.

Her Majesty's carriage, drawn by four horses-the front left ridden by a postilion-was already on the path a little way ahead. There were four outriders with her, two in front of the vehicle and two some yards behind it.

Trounce increased his pace to catch up, walking down a gentle slope that gave him an excellent view of the scene.

Despite the mild weather, the crowd was sparse today. There were no protests and few hurrahs.

He jumped at the sound of a gunshot.

What the hell?

Breaking into a run, he scanned the scene ahead and saw a man wearing a top hat, blue frock coat, and white breeches walking beside, and to the right of, the slow-moving carriage. He was throwing down a smoking flintlock and drawing, with his left hand, a second gun from his coat.

In an instant, horror sucked the heat from Trounce's body and time slowed to a crawl.

His legs pumped; his boots thudded into the grass; he heard himself shout, "No!"

He saw heads turning toward the man.

His breath thundered in his ears.

The man's left arm came up.

The queen stood, raising her hands to the white lace around her throat.

Her husband reached for her.

A second man leaped forward and grabbed the gunman.

"No, Edward!" came a faint yell.

The scene seemed to freeze; the two men entwined; their faces, even from this distance, so similar, like brothers; each person in the crowd poised in midmotion, some stepping forward, some stepping back. The queen standing, wearing a cream-coloured dress and bonnet. Her consort leaning forward, in a top hat and red jacket. The outriders turning their horses.

Christ! thought Trounce. Christ, no! Please, no!

Suddenly a freakish creature flew past him.

What the hell? A-a stilt-walker?

Tall, loose-limbed, bouncing on what seemed to be spring-loaded stilts, it stopped just ahead of the constable, who stumbled and fell to his knees.

"Stop, Edward!" the weird apparition bellowed.

A bolt of lightning shot from its side into the ground and the lean figure staggered, groaning and clutching at itself.

Below, the two struggling men turned and looked up.

A puff of smoke from the pistol.

Blood spraying from Queen Victoria's head.

"Merciful heaven!" gasped Trounce.

A detonation echoing away over the park; rippling into the distance, taking with it the consequences of the heinous act; history, quite literally, in the making; expanding outward to envelop the Empire.

"No," groaned the stilt-walker. "No!"

It turned and Trounce saw the face: crazy eyes, a thin blade of a nose, a mouth stretched into a rictus grin, drawn and lined features, pale beneath a sheen of sweat, twisted in agony.

The thing was wearing a big round black helmet and a black cloak beneath which there was a white, tight-fitting bodysuit. Some sort of flat lantern hung on the chest, spitting fire. There were scorch marks on the material around it.

The odd figure bobbed on the short stilts then bounded forward and leaped right over the police constable's head.

Trounce toppled onto the grass, rolled over, and looked behind him. The costumed figure was nowhere to be seen. It had vanished.

Christ Almighty. Christ Almighty.

Screams.

Trounce looked down the slope.

Victoria had flopped backward out of the carriage onto the ground. Her husband was scrambling after her.

The assassin was still struggling with the other man but, as Trounce watched, the gunman was suddenly thrown off his feet by his assailant. His head hit the low wrought-iron fence that bordered the path. He went limp and lay still.

The crowd surged around the royal carriage. The outriders plunged through the throng and attempted to hold the panicked people back, away from the stricken monarch. A police whistle blew frantically.

That's me, thought Trounce. That's me blowing the whistle.

A figure detached itself from the mob and started running across the park, northwestward, heading for Piccadilly.

It was the man who'd grappled with the assassin.

Trounce took off in pursuit. It seemed the right thing to do.

The thought occurred to him that police-issue boots were ill designed for running.

"For goodness' sake!" he gasped to himself. "Concentrate!"

He raced past the outriders.

A dazed young man, squinting through a monocle, wandered into his path and Trounce barrelled into him, shoving him aside with a curse.

His quarry angled up a slope and disappeared into the heavily wooded upper corner of the park. Trounce grunted with satisfaction; he knew there was a high wall behind those trees.

He was breathing heavily and had a stitch in his side by the time he got to the edge of the woods. He stopped there, gulping air, eyeing the gloomy spaces beneath the boughs, listening for movement.

Distant screams and shouts were sounding from behind him. Police whistles were blasting from different points around the park as constables converged on the scene.

A rustle came from the trees. A movement.

Trounce took hold of his truncheon.

"Step out into the open, sir!" he commanded. "I saw what happened; there's nothing to worry about. Come on, let's be having you!"

No reply.

"Sir! I saw you trying to protect the queen. I just need you to-"

There was a flurry of leaves, and suddenly Trounce found himself confronted by the stilt-walking man again, leaping out of the thicket.

Taken by surprise, Trounce stepped back, lost his footing, and fell onto his bottom.

"How-how-?" he stuttered.

The thing phantom, devil, illusion, whatever it was-crouched as if to spring.

Reflexively, Trounce whipped his arm back and hurled his truncheon at it. The club struck the creature in the chest, hitting the lamplike object affixed there. Fiery sparks erupted and rained onto the grass. The apparition stumbled.

"Damn!" it cursed in a clear human voice, then turned and sprang to the constable's right, leaping away in huge bounds.

Trounce got to his feet and watched the thing heading eastward. It took a massive leap into the air and, twenty feet above the ground, winked out of existence. The air seemed to fold around it.

Trounce stood, his arms dangling at his sides, his mouth open and his eyes wide.

A minute passed before, as if waking from a dream, he roused himself and looked down the sloping grass to the royal carriage. Then he looked back at the thicket. His quarry-the man who had tackled the assassin-must still be in there somewhere.

He entered the trees and began to search, calling, "There's no point hiding, sir. Please show yourselfl"

Ten minutes later he admitted defeat. He'd found a top hat lying on the ground, but that was all. The man had escaped.

He trudged down the slope toward the chaotic scene below, his mind blank.

Other constables had arrived and were pushing the growing crowd back, helped by the queen's outriders.

Trounce pushed past the onlookers-some silent, some sobbing, some talking in hushed tones, some shouting or screaming-and crossed to where the assassin lay. The man's head was pinned to the top of the low railings, held at an awkward angle, the spike of an upright projecting from his left eye, blood pooling beneath. It was a grisly sight.