The second curious fact was discovered by Inspector Whyland almost by accident. In his study of Mr. Copperdock and his associates, he had taken to frequenting the saloon bar of the Cambridge Arms, carefully choosing such times as Mr. Copperdock was busy in the shop. There was nothing in any way suspicious about the Cambridge Arms; it lay in one of the streets which run southwards from Praed Street, and was consequently almost hidden in a backwater. Its remarkably cosy little saloon bar was patronized chiefly by the neighbouring small tradesmen, and its habitués were all well-known to the proprietor, with whom Whyland soon became on confidential terms.

A couple of days after the inquest on Richard Pargent, Whyland turned into the Cambridge Arms just as its doors were opened, at five o’clock. The proprietor met him with a smile, and, having executed his order, leant over the bar and entered into conversation.

“I never thought, when I opened up last Saturday, that that poor fellow was being murdered at that very minute,” he began. “Just about five o’clock, wasn’t it, sir?”

Whyland nodded. “The clock was striking five as they picked him up,” he replied.

“I remember the evening well,” continued the proprietor. “Though it wasn’t until nigh upon seven that I heard anything about it. I says to my wife it was that wet and foggy that even our regulars wouldn’t be in till later. But there you are, you never can tell. I hadn’t opened this bar, not more than five minutes, when in comes one of my best customers, Sam Copperdock, the tobacconist. You may have met him here, sir?”

Whyland nodded non-committally, and the landlord proceeded.

“I was a bit surprised to see him, sir, because Sam doesn’t usually come along until eight, unless it happens to be Thursday, when he closes early. ‘Hullo, Sam, you’re on time to-night,’ I says, jocular like. ‘Oh, I’ve only come in for a drink,’ he says; ‘The bottle’s empty at home, and I couldn’t scrounge one from old Ludgrove opposite, he’s away.’ He has a double, and goes back to his shop. The bar was pretty nigh empty till about seven, when a fellow comes in and tells me about the murder.”

Inspector Whyland deftly turned the conversation. He knew that if he questioned the man his suspicions would be aroused, and this he was anxious to avoid. Without any appearance of haste he finished his drink and left the premises. Once round the corner, he walked swiftly to the spot where Richard Pargent had been murdered, counting his paces as he went.

Could Mr. Copperdock have committed the murder? It was quite possible. If he had left his shop a few minutes before five, he would have had plenty of time to reach the exit from Paddington station, plunge the knife into his victim, and be at the Cambridge Arms at five minutes past. But, if he were the criminal, a thousand puzzling questions presented themselves. How did he know that his victim would be arriving at Paddington at 4.55 that evening? Above all, why should Mr. Copperdock, the tobacconist, have any grudge against Mr. Pargent, the minor poet? And then again, Whyland was convinced that the murderer of Richard Pargent had been the murderer of James Tovey. But, at the moment when Tovey had been killed, Mr. Copperdock was in his sitting-room with his son and the murdered man’s daughter. The riddle appeared to be insoluble.

Whyland turned abruptly, boarded a bus, and took a ticket to Oxford Circus. Here he dismounted, and turned into the first picture-house which presented itself. He had discovered long ago that this was the surest way of securing freedom from interruption. Here for a couple of hours he sat motionless, neither seeing the pictures nor attentive to the strenuous efforts of the orchestra. And as he sat, a new theory slowly unfolded itself in his brain.