Frant nodded. “He was in a ghastly state when he was brought in,” he went on. “The station doctor had to give him a pretty stiff dose of morphia or he’d have gone off his head. I really felt sorry for the blackguard. It seems that he’s been an addict for years, but since the crash of the company and Ballantine’s death, worry and fright have so wrecked his nerves that he’s been increasing the doses until he’d used up all his supply—and his customers’ too. That’s why he sent Eales over today. It’s a very useful capture, and if the French police play up, we ought to be able to round up a whole gang on both sides of the Channel.”

Mallett rubbed his hands in satisfaction.

“The end of a perfect day,” he purred. “I think we’ve both earned a cup of tea.”

“And now,” said Frant as they sat down to tea, “would you mind telling me, just for my own information, what you have done and just how you managed to get to the bottom of this?”

“Pure—what is the word?—ratiocination,” answered the inspector proudly. “I approached it this way. There were several people who might have killed Ballantine. Of them all the one who took my fancy from the start was Fanshawe. Apart from the question of motive, he was the only man who seemed to me to be of the stuff of which murderers are made. Not that he is a common sort of killer by any means; on the contrary, I should put him down as a distinctly superior type—high-minded, fastidious, and all the rest of it. But vain, Frant, vain—or, if that’s too small a word, proud as Lucifer. The sort of man who, if he decided that someone else ought to be wiped out would think no more of doing it than of squashing a fly on the window-pane. That was my first reflection.