In forty minutes the same taxi put him down in Wigmore Street. This time he had two plain-clothes sergeants with him. Dr. Roberts’s little butler opened the door. His face was terribly white. He looked at Alleyn without speaking and then stood aside. Alleyn, followed by his men, walked into the drawing-room. Roberts stood in front of the fireplace. Above him the picture of the little lake and the Christmas trees shone cheerfully in the lamplight. Fox stood inside the door and Boys near the window. The anæsthetic apparatus had been wheeled over by the desk.

When Roberts saw Alleyn he tried to speak, but at first could not. His lips moved as though he was speaking, but there were no words. Then at last they came.

“Inspector Alleyn—why—have you sent these men-after me?”

For a moment they looked at each other.

“I had to,” said Alleyn. “Dr. Roberts, I have a warrant here for your arrest. I must warn you—”

“What do you mean?” screamed Roberts. “You’ve no grounds—no proof—you fool—what are you doing?”

Alleyn walked over to the thing like a cruet. He stooped down, unscrewed something that looked like a nut and drew it out. With it came a hypodermic syringe. The “nut” was the top of the piston.

“Grounds enough,” said Alleyn.

It took the four men to hold Roberts and they had to put handcuffs on him. The insane are sometimes physically very strong.

CHAPTER EIGHTEEN

Retrospective

Saturday, the twentieth. Evening.

TWO EVENINGS AFTER the arrest Alleyn dined with Nigel and Angela. The inspector had already been badgered by Nigel for copy and had thrown him a few bones to gnaw. Angela, however, pined for first-hand information. During dinner the inspector was rather silent and withdrawn. Something prompted Angela to kick Nigel smartly on the shin when he broached the subject of the arrest. Nigel suppressed a cry of pain and glared at her. She shook her head slightly.

“Was it very painful, Bathgate?” asked Alleyn.

“Er—oh—yes,” said Nigel sheepishly.

“How did you know I kicked him?” Angela inquired. “You must be a detective.”

“Not so that you would notice it, but perhaps I am about to strike form again.”

“Hullo—all bitter, are you? Aren’t you pleased with yourself over this case, Mr. Alleyn?” Angela ventured.

“One never gets a great deal of gratification from a fluke.”

“A fluke!” exclaimed Nigel.

“Just that.”

He held his glass of port under his nose, glanced significantly at Nigel and sipped it.

“Go on,” he said resignedly. “Go on. Ask me. I know perfectly well why I’m here and you don’t produce a wine like this every evening. Bribery. Subtle corruption. Isn’t it, now?”

“Yes,” said Nigel simply.

“I won’t have Mr. Alleyn bullied,” said Angela.

“You would if he could,” rejoined Alleyn cryptically. “I know your tricks and your manners.”

The others were silent.