It was by that time past one o’clock, and Jettison turned into the small hotel at which he had lodged himself.  He thought much and gravely while he ate his dinner; he thought still more while he smoked his after-dinner pipe.  And his face was still heavy with thought when, at three o’clock, he walked into Mitchington’s office and finding the inspector alone shut the door and drew a chair to Mitchington’s desk.

“Now then,” he said.  “I’ve had a rare morning’s work, and made a discovery, and you and me, my lad, have got to have about as serious a bit of talk as we’ve had since I came here.”

Mitchington pushed his papers aside and showed his keen attention.

“You remember what that young fellow told us last night about that man Collishaw paying in fifty pounds to the Second Friendly two days before his death,” said Jettison.  “Well, I thought over that business a lot, early this morning, and I fancied I saw how I could find something out about it.  So I have—­on the strict quiet.  That’s why I went to the Friendly Society.  The fact was—­I wanted to know in what form Collishaw handed in that fifty pounds.  I got to know.  Gold!”

Mitchington, whose work hitherto had not led him into the mysteries of detective enterprise, nodded delightedly.

“Good!” he said.  “Rare idea!  I should never have thought of it!  And—­what do you make out of that, now?”

“Nothing,” replied Jettison.  “But—­a good deal out of what I’ve learned since that bit of a discovery.  Now, put it to yourself—­whoever it was that paid Collishaw that fifty pounds in gold did it with a motive.  More than one motive, to be exact—­but we’ll stick to one, to begin with.  The motive for paying in gold was—­avoidance of discovery.  A cheque can be readily traced.  So can banknotes.  But gold is not easily traced.  Therefore the man who paid Collishaw fifty pounds took care to provide himself with gold.  Now then—­how many men are there in a small place like this who are likely to carry fifty pounds in gold in their pockets, or to have it at hand?”

“Not many,” agreed Mitchington.

“Just so—­and therefore I’ve been doing a bit of secret inquiry amongst the bankers, as to who supplied himself with gold about that date,” continued Jettison.  “I’d to convince ’em of the absolute necessity of information, too, before I got any!  But I got some—­at the third attempt.  On the day previous to that on which Collishaw handed that fifty pounds to Stebbing, a certain Wrychester man drew fifty pounds in gold at his bank.  Who do you think he was?”

“Who—­who?” demanded Mitchington.

Jettison leaned half-across the desk.

“Bryce!” he said in a whisper.  “Bryce!”

Mitchington sat up in his chair and opened his mouth in sheer astonishment.

“Good heavens!” he muttered after a moment’s silence.  “You don’t mean it?”

“Fact!” answered Jettison.  “Plain, incontestable fact, my lad.  Dr. Bryce keeps an account at the Wrychester bank.  On the day I’m speaking of he cashed a cheque to self for fifty pounds and took it all in gold.”