"It nearly fell through; because, you see, we confronted Spinelli with Langdon, and they had the opportunity to confer in private. You can understand now Langdon's horror and nervousness when I announced that Spinelli was ready to talk. He thought I meant talk of what he knew about the girl. But the girl's scheme worked because Langdon's suspicions were aroused at Spinelli's talk, and he wondered whether 'Betty Depping' mightn't have deeper reasons for wishing silence all around than that matter of her identity.
"We shall never know what passed between Spinelli and Langdon at their interview. Langdon realized that Spinelli knew something more; but he kept his own counsel, and determined to be present that night — unseen and unheard — at the rendezvous between Spinelli and the girl."
Dr. Fell threw his cigar into the fire. He leaned back and listened to the rain.
They were both marked," he said. "You know what happened."
"Moral observations," remarked J. R., after a silence, "are now in order. Somebody will have to talk for a page or two on the futility and sadness of it, and how she would have been safe if only she hadn't left one-little-damning clue behind…"
"It won't go, Fm afraid," said Dr. Fell. He chuckled. The one-little-damning clue was a large and many-caloried dinner, steaming before your noses. You might as well say that the Guiness advertisements plastered over the hoardings are a clue to the theory that somebody is trying to sell stout."
J. R. scowled. "All the same," he said, "Fm glad that the only detective plot in which I ever took part was not full of improbabilities and wild situations, like-well, like Morgan's Murder on the Woolsack or Aconite at the Admiralty. There are no fiendish under-clerks shooting poisoned darts through keyholes at the First Sea-Lord, or luxurious secret dens of the. Master Criminal at Limehouse. What I mean by probability…"
Hugh looked round in some surprise to see that Morgan was gurgling with rage.
"And you think," Morgan inquired, "that this is a probable story?"
"Isn't it?" asked Hugh. "It's exactly like one of those stories by William Block Tournedos. As Mr. Burke says…"