“If he chewed it up,” said Shelley, “it would be obvious enough that there was something queer about the sweet. But he would attribute it to something wrong with the making of the thing, and would probably want to spit it out and throw it away. But before he had time to do that the cyanide would be in his system. He would be sleeping his last sleep before the thought of poison really had time to penetrate his mind.”

“Think so?” Cunningham was still mildly incredulous.

“Certain.” Shelley was emphatic. “I’m perfectly sure that Professor Arnell was fond of almonds, that some person at present unknown was aware of his little weakness, and that he was given a good hefty dose of cyanide in an almond. There’s the crime in a nutshell. Whether that person unknown is Mr. Fairhurst’s mysterious young lady is the thing that we have first to find out. But meanwhile let’s see what we can find about the late Professor Arnell from the reference books.”

He touched a bell on the table, and an assistant came silently in. “Can you get me a copy of Who’s Who, and the Royal Literary Society’s Handbook?” asked Shelley. In a minute or less the books were before them.

Shelley rapidly scanned the correct pages of the reference books, and made rapid notes.

“Well, sir?” asked Cunningham.

“Professor Arnell lived at Pinner,” said Shelley. “He was Professor Emeritus at Portavon—in other words, he had retired from active life—and he apparently lived with his daughter. Query, Cunningham: is Miss Arnell the mysterious lady seen by our Mr. Fairhurst?”

“Any other pointers?”

“There may be more in this case than meets the eye, Cunningham,” said Shelley.

“Why?”

“Do you remember Arnell, the oil millionaire? Owned half of the State of Texas, then sold out, and came to England to live twenty or thirty years ago?”

“The name seems familiar to me in some way,” Cunningham admitted.

“He died two years ago,” said Shelley. “I remember the report in the papers quite clearly.”

“But what’s that to do with this case, sir?” asked Cunningham.

“A lot,” said Shelley crisply. “He was Professor Arnell’s father.”

“Yes?” The question was implied in Cunningham’s intonation.

“When a millionaire dies in mysterious circumstances,” said Shelley, “look for the money motives, Cunningham.”

“And what are the money motives here?”

“That’s what we have to find out,” said Shelley.

But it was to be a long time before they disentangled the web of mystery. And in the meantime Henry Fairhurst was doing his bit.

Chapter III

Chapter III

Henry at Home

“Really, Henry, I do think this is most unreasonable of you.”