But this subconscious neurasthenia in no wise affected the reflex action of his ordinary faculties. When, on leaving the square, and while his cab was rattling along an aristocratic thoroughfare leading to Knightsbridge, he peered through a tiny observation window in the back of the vehicle, and ascertained that the gray car was stealing along quietly about a hundred yards in the rear, he began to believe that its presence both at Waterloo and outside Mr. Forbes's residence could not be wholly accidental. When he had watched its persistent treading on his heels along Piccadilly its intent became almost unmistakable.
The route to Innesmore Mansions traversed some of London's main arteries, but, despite the rush of traffic due to the first flight of homeward-bound playgoers, the gray car kept steadily on his track. Amused at first, he became angry because of a notion which grew out of the wonderment of finding himself the object of this persistent espionage.
To make sure, and at the same time discover the sort of person who was spying on him, he adopted a ruse. Leaning out, when about to cross Oxford Street into Tottenham Court Road, he said to his driver: "Turn sharp to the right in Store Street, and pull up. I'll tell you when to go on again."
The man obeyed. Theydon posted himself at the outer window, and in a space of time so short that the excellence of the gray car's accelerator was amply demonstrated, the pursuer swung into sight. A stolid-faced chauffeur at the wheel did not appear discomfited at coming on his quarry thus unexpectedly. He whirled past, seemingly quite oblivious of Theydon's fixed stare. Though the weather was mild he wore an overcoat with upturned collar, so that between its protecting flaps and a low-peaked cap his face was well hidden. Still, Theydon received an impression of a curiously wooden physiognomy.
The man might have been an automaton for all the heed he gave to the taxi or its inquisitive occupant. But his aspect was almost forgotten in the far stranger discovery that the car was empty. Both windows were open, and the bright lights of a corner shop flashed into the interior, yet not a soul was visible. Moreover, the car sped on unhesitatingly, stopping some two hundred yards ahead.
So far as Theydon could tell, no one alighted. He jotted down the number—XY 1314—on his shirt cuff.
"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.
"The cigars are genuine Havanas," he said. "A birthday present from a maiden aunt, who is wise enough to judge the quality of tobacco by the price. Here, too, are Virginian, Turkish and Egyptian cigarettes."
Winter inspected the cigars gravely.
"By Jove!" he cried, his big eyes bulging in joyous surprise. "Last year's crop from the Don Juan y Guerrero plantation. Treasure that aunt of yours, Mr. Theydon. None but herself can be her equal."
Theydon saw that the little man did not follow his chief's example.
"Don't you smoke?" he said.
"No, but if you'll not be horrified, I would like to smell one of those Turks."
"Smell it?"
"Yes. That is the only way to enjoy the aroma and avoid nicotine poisoning. My worthy chief dulls a sound intellect by the cigar habit. What is worse, he excites a nervous system which is normally somewhat bovine. You, also, I take it, are a confirmed smoker, so both of you are at cross-purposes already."
Furneaux's voice was pitched in the curious piping note usually associated with comic relief in a melodrama, but his wizened face was solemn as a red Indian's. It was Theydon who smiled. His preconceived ideas as to the appearance and demeanor of the London detective were shattered. Really, there was no need to take these two seriously.
Winter, while lighting the cigar, grinned amiably at his colleague. Furneaux passed a cigarette to and fro under his nostrils and sniffed. Theydon reached for a pipe and tobacco jar and drew up a chair.
"Well," he said, "it is not my business to criticise your methods. I have very little to tell you. I suppose Bates—"
"The really important thing is this car which followed you tonight," broke in Winter. "The details are fresh in your memory. What type of car was it? Did you see the driver and occupants? What's its number?"
Theydon had not expected these questions. He looked his astonishment.
"Ha!" cackled Furneaux. "What did I tell you?"
"O, shut up!" growled Winter. "I am asking just what you yourself are itching to know."
"May I take it that the car has not been dogging me by your instructions?" said Theydon. He was inclined to be skeptical, yet the Chief Inspector seemed to have spoken quite candidly.
"Yes," said Winter, meeting the other's glance squarely. "We have no reason on earth to doubt the truth of anything you have said, or may say, with regard to this inquiry. The car is not ours. This is the first we have heard of it. We accepted your word, Mr. Theydon, that you were dining with a friend. Perhaps you will tell us now what his name is and where he lives."
Theydon