“No, these are only business letters. There doesn’t appear to be anything out of the ordinary here at all.”

Roger still held the book mechanically in his hand, but he was staring blankly at the wall.

“Nothing but cash,” he murmured softly; “all sorts of sums between £10 and £5,000; each sum a multiple of ten, or some other round figure; no shillings or pence; and cash! That’s what worries me. Why cash? I can’t find a single check marked on the credit side of these three books. And where in the name of goodness did all this cash come from? There’s absolutely nothing to account for it, as far as I can make out. It’s not the proceeds of any sort of business, apparently. Besides, the debit side shows nothing but checks drawn to self. He paid it in as cash and he drew it out himself. Now what on earth does all this mean?”

“Don’t ask me,” said Alec helplessly.

Roger stared at the wall in silence for a few minutes. Suddenly, his mouth opened, and he whistled softly.

“By—Jove!” he exclaimed, transferring his gaze to Alec. “I believe I’ve got it. And doesn’t it simplify things, too? Yes, it must be right. It makes everything as clear as daylight. Good lord! Well, I’m damned!”

“Out with it, then!”

Roger paused impressively. This was the most dramatic moment he had yet encountered, and he was not going to spoil it by any undue precipitation.

He smote the table softly with his fist by way of preparation. Then:

“Old Stanworth was a professional blackmailer!” he said in vibrant tones.