“Perhaps I am not the best man to explain all this,” I said.

“No,” said a voice from the doorway. “Allow me.”

Holmes surged to his feet. “And who are you?”

“My name is Mycroft Holmes.”

“Impostor!” declared my companion.

“I assure you that that is not the case,” said Mycroft. “I grant I’m not your brother, nor a habitué of the Diogenes Club, but I do share his name. I am a scientist — and I have used certain scientific principles to pluck you from your past and bring you into my present.”

For the first time in all the years I had known him, I saw befuddlement on my companion’s face. “It is quite true,” I said to him.

“But why?” said Holmes, spreading his long arms. “Assuming this mad fantasy is true — and I do not grant for an instant that it is — why would you thus kidnap myself and my good friend, Dr. Watson?”

“Because, Holmes, the game, as you used to be so fond of saying, is afoot.”

“Murder, is it?” asked I, grateful at last to get to the reason for which we had been brought forward.

“More than simple murder,” said Mycroft. “Much more. Indeed, the biggest puzzle to have ever faced the human race. Not just one body is missing. Trillions are. Trillions.”

“Watson,” said Holmes, “surely you recognize the signs of madness in the man? Have you nothing in your bag that can help him? The whole population of the Earth is less than two thousand millions.”

“In your time, yes,” said Mycroft. “Today, it’s about eight thousand million. But I say again, there are trillions more who are missing.”

“Ah, I perceive at last,” said Holmes, a twinkle in his eye as he came to believe that reason was once again holding sway. “I have read in The Illustrated London News of these dinosauria, as Professor Owen called them — great creatures from the past, all now deceased. It is their demise you wish me to unravel.”