“Did you happen to see that car waiting near the house I came from?” he said to the taxi man, who, of course, provided an interested audience of one.

“Yes, sir,” was the ready answer.  “It’s not a London car.  I’ve never seen them letters afore.”

“In other words, it may be a faked number.”

“Likely enough, sir, but rather risky.  The police are quick at spotting that sort of thing.”

“Can you take a hand in the game?  I want to know where that car goes to.”

The man grinned.

“I wouldn’t like to humbug you, sir.  That there machine can lose me quicker’n a Derby winner could pass a keb horse.  Didn’t you hear the hum of the engine as it went by?”

“Thanks.  Now go ahead to Innesmore Mansions.”

He was paying the driver when the gray car stole quietly past the end of the street, and that was the last he saw of it.

“There it goes again, sir,” said the man.  “Tell you wot, gimme your name an’ address.  I’ll make a few inquiries, an’ keep me eyes open as well.  Then, if I hear anythink, I’ll let you know.”

Theydon scribbled the number of his flat on a card.

“There you are,” he said.  “Even if I happen to be out, I’ll leave instructions that you are to be paid half a crown for your trouble if you call.  By the way, what is your name?”

“Evans, sir.”

There was really little doubt in Theydon’s mind as to the reason why he had been followed.  He was fuming about it when Bates met him in the hall of No. 18 with the whisper: 

“Them two are waiting here now, sir.”

Theydon glanced at his watch.  The hour was ten minutes past eleven.

“Sorry I’m late, gentlemen,” he said, on entering the sitting room and finding the detectives seated at his table, seemingly comparing notes, because the Chief Inspector was talking, while Furneaux, the diminutive, was glancing at a notebook.

“We have no reason to complain of being kept waiting a few minutes in such comfortable quarters,” said Winter pleasantly.

“O, I fancy I was detained by some zealous assistant of yours,” said Theydon, determined to carry the war into the enemy’s territory.

At that Furneaux looked up quickly.

“Will you kindly tell me just what you mean, Mr. Theydon?” said Winter.

“Why?  Is it news to you that a gray limousine car stalked me from Waterloo to—­ to my friend’s house, waited there three hours or more, and has carefully escorted me home?  I dislike that sort of thing.  Moreover, it strikes me as stupid.  I didn’t kill Mrs. Lester.  It will save you and me a good deal of time and worry if you accept that plain statement as a fact.”

“Won’t you sit down?” said Winter quietly.  “And—­ may I smoke?  I didn’t like to ask Bates for permission to light up in your absence.”

Theydon was not to be outdone in coolness.  He opened a corner cupboard and produced various boxes.