Why it was so, I can’t say, but McMurtrie’s politeness always filled me with a feeling of repulsion.  There was something curiously sinister about it.

He stepped forward into the room, followed by Savaroff, who closed the door behind him.  The latter then lounged across and sat down on the window-sill, McMurtrie remaining standing by my bedside.

“You have read the Mail, I see,” he said, picking up the paper.  “I hope you admired the size of the headlines.”

“It’s the type of compliment,” I replied, “that I have had rather too much of.”

Savaroff broke out into a short gruff laugh.  “Our friend,” he said, “is modest—­so modest.  He does not thirst for more fame.  He would retire into private life if they would let him.”

He chuckled to himself, as though enjoying the subtlety of his own humour.  Unlike his daughter, he spoke English with a distinctly foreign accent.

“Ah, yes,” said Dr. McMurtrie amiably; “but then, Mr. Lyndon is one of those people that we can’t afford to spare.  Talents such as his are intended for use.”  He took off his glasses and began to polish them thoughtfully.  “One might almost say that he held them in trust—­in trust for Providence.”

There was a short silence.

“And is it on account of my talents that you have been kind enough to shelter me?” I asked bluntly.

The doctor readjusted his pince-nez, and seated himself with some deliberation on the foot of the bed.

“The instinct to assist a hunted fellow-creature,” he observed, “is almost universal.”  Then he paused.  “I take it, Mr. Lyndon, that you are not particularly anxious to rejoin your friends in Princetown?”

I shook my head.  “Not if there is a more pleasant alternative.”

Savaroff grunted.  “No alternative is likely to be more unpleasant for you,” he said harshly.

The touch of bullying in his tone put my back up at once.  “Indeed!” I said:  “I can imagine several.”

McMurtrie’s smooth voice intervened.  “But ours, Mr. Lyndon, is one which I think will make a very special appeal to you.  How would you like to keep your freedom and at the same time take up your scientific work again?”

I looked at him closely.  For once there was no trace of mockery in his eyes.

“I should like it very much indeed, if it was possible,” I answered.

McMurtrie leaned forward a little.  “It is possible,” he said quietly.

There was a short pause.  Savaroff pulled out a cigar, bit off the end, and spat it into the fireplace.  Then he reached sideways to the chest of drawers for a match.

“Explain to him,” he said, jerking his head towards me.

McMurtrie glanced at him—­it seemed to me a shade impatiently.  Then he turned back to me.

“For some time before Mr. Marks’s unfortunate death,” he said slowly, “you had been experimenting with a new explosive.”