The moment the dragon appears on the stage of The Egyptian Hall theater in London, Sherlock Holmes knows there is something truly wonderful, truly disturbed, about Alistair Hemsworth. It is the late summer of 1869, and the boy feels as if he is a man. He is dressed in a coal- black, impeccably cleaned and brushed secondhand frock coat, the first of his life; all its predecessors were much older. Sitting beside him with her mouth as wide as his, celebrating her sixteenth birthday, is Irene Doyle. And she is the most beautiful girl, no, the most beautiful woman, in all of England. Theirs has been a tempestuous relationship, but lately everything has changed. They have been walking out together, she boldly defying her father’s wishes, he (seven months her junior), unrestricted in his movements due to the liberal ways of his mentor, the extraordinary Denmark Street apothecary, Sigerson Bell.

Sherlock had been surprised when she told him that this was her birthday and how old she would be turning. He had assumed that she was younger than he. Girls, he was learning, are full of surprises.

But not even they can make a dragon appear.

There are screams in the crowd. Alistair Hemsworth stands in front of jungle trees, a hand on his hip, his chest thrust out, his other arm raised, his index finger pointing at . . . the writhing beast that has materialized on the stage. It is rising up, it seems, from the depths of the underworld below the theater, a remarkable illusion. Even Sherlock can’t figure how he has done it. The dragon hisses, it twists in its cage, three- dimensional and rubbery, a muddy green- gray with golden wings – more than eight feet long from head to tail. Women are staggered by it; they shriek and lean on their gentlemen. But Irene Doyle stands upright. Her face is glowing, lit up with excitement, and as she looks at Sherlock and takes his hand, he glows back.

The dragon’s hiss seems to have come from backstage and its wings appear to be flapping mechanically – Sherlock thinks he can see thin black strings attached to the wings against the dark backdrop. And yet, the beast appears to be so real! Instead of fire coming from its mouth, a red tongue, forked at the tip and more than a foot long, darts out in a realistic manner, and its shining eyes glare at the audience, animated more by God, it seems, than any human being, no matter how ingenious. If this isn’t a dragon, then it is surely an ancient dinosaur . . . somehow brought to life on The Egyptian Hall stage!

Then a sight even more sensational than the dragon appears inside the cage with the beast. A woman, wearing a headdress and a purple Egyptian robe that is tied back to reveal a skimpy white muslin costume underneath, rises to her feet on long, bare legs and stands in front of the dragon! She looks terrified. Hemsworth has put his assistant into the cage with the creature! Her hands are tied behind her back, her mouth gagged and bound. She cries out, but help! is the only word that is recognizable. The screams increase from the audience. Women faint, falling back into their seats. Irene squeezes Sherlock’s hand.

Hemsworth turns to the giant lizard and produces a sword out of thin air. “In days of old, the venerable saint slew the dragon at the very moment it approached the princess,” he cries, “saving both her . . . and his people!”

The dragon is trying to get at the woman. It is shackled and tethered, but as it strains it seems about to break loose. Will it devour her alive, here on the stage in front of all these people?

“BE GONE!” shouts Hemsworth, shaking his sword at the creature.

Everything – the dragon, the princess, and the cage – vanishes from the stage.

The applause is thunderous.

London has never considered Alistair Hemsworth to be a great magician. No one would rank him among any of the legends now plying their arts in this golden age of magic on the city’s stages. Yet, this year, throngs of spectators are coming to see him in never- ending queues.

He was not, like most of the others, born to the profession. In fact, just a few years earlier, he was known, if known at all, as an adventurer. Not a great man like Burton or Speke, the likes of whom braved darkest Africa, made significant discoveries, and brought glory to the empire. He was a different and lower sort – an explorer whose exploits were printed in short notes on the back pages of The Times of London, a dealer in human cargo who found freaks in Oriental jungles for English showmen. It was even whispered that he sometimes dealt in the ignominious and illegal trading of slaves . . . of any skin color.

His dream, however, he has been reporting to the newspapers during this season of his great success – has always been to be a famed illusionist. An amateur magician since childhood, he long ago vowed that he would become the theatrical sensation that he is today.

But his show is built on a single moment. Everyone in London knows it.

Sherlock and Irene had sat through his fumbling attempt at levitating a female audience member, his awkward sawing and cutting up of another lady, and the amateurish removal of his own head, an obviously fake, porcelain object, severed from his trunk by his beautiful African assistant, and then nearly dropped on the stage boards as he tried to hold it aloft. But no one laughed, no one booed. Not a word was spoken. Everyone waited for the dragon. And when it came, it didn’t disappoint.

The instant the beast and its “victim” vanish, the lights come up. Hemsworth is gone too. There is a buzz in the crowd, voices filling the grand, Egyptian- themed amphitheater with its rich red curtains and white pillars.

“Come!” says Irene, taking Sherlock by the hand again, something he has gotten used to lately; something, he has to admit, he greatly enjoys.

Bit by bit, over the preceding eighteen months, ever since he was involved in the case of the Spring Heeled Jack, he has been allowing her back into his life. On the night he solved that crime, a stunning chance meeting on the streets with Prime Minister Disraeli had ushered in other changes too. Sherlock had been nearly undone by the frightening events of that evening, but the great man urged him to keep pursuing his dreams. And so, instead of staying out of dangerous criminal cases until he was older, as he had been telling himself he should, or rashly throwing himself into them, as he seemed driven to do, he decided to try a different tack: continue to apply himself and his great gifts, even at this young age, to the cause of justice. (After all, this will be his life’s work, so he must train.) But until he becomes a man, he must do so only at arm’s length. Thus he began, that day, to help the police whenever he could, but in a new way: by investigating crimes from a distance . . . and then dropping clues to Inspector Lestrade’s son (who happily promised to keep his source to himself ).

Sherlock and his employer have had a marvelous time with this at the old apothecary shop. Mr. Bell is turning out to be a cunning parlor- room detective indeed, though the boy often thinks that the old man dearly misses helping him collar the criminals in person. Bell is fond of recounting his hand- to- hand combat with the Spring Heeled Jack on the cobblestones of a Bethnel Green rookery.

“My boy! It was a fine bit of Bellitsu, was it not? I believe he must have soiled himself with fear when he saw me approaching, warrior cloth wrapped to my cranium, warrior tights gripping my manly thighs, the muscles in my buttocks tensed like the coils of –”

“We don’t need to retell that part, sir.”

“. . . We don’t?”

“No sir, too much information always spoils a good story.”

“Yes, well, you may be correct, my young knight. Be that as it may, it was indeed a tight spot we were in that night and I well recall that . . .”

On and on he would go, until Sherlock would get up and leave the room, the old man still holding forth. More often than not, Sigerson Bell would be fast asleep when the boy returned.