l him yet. The old incredulity returned and methodically he
re-examined the contents of some of the table drawers. Ere long,
however, he desisted impatiently.

"What the devil could a penniless doctor have hidden in his desk that
was worth stealing!" he said aloud. "I must avoid cold salmon and
cucumber in future."

He tossed the statement aside and turned to his scientific paper.

There came knock at the door.

"Come in!" snapped Stuart irritably; but the next moment he had turned,
eager-eyed to the servant who had entered.

"Inspector Dunbar has called, sir."

"Oh, all right," said Stuart, repressing another sigh. "Show him in
here."

There entered, shortly, a man of unusual height, a man gaunt and
square both of figure and of face. He wore his clothes and his hair
untidily. He was iron grey and a grim mouth was ill concealed by the
wiry moustache. The most notable features of a striking face were the
tawny leonine eyes, which could be fierce, which could be pensive and
which were often kindly.

"Good evening, doctor," he said--and his voice was pleasant and
unexpectedly light in tome. "Hope I don't intrude."

"Not at all, Inspector," Stuart assured him.

"Make yourself comfortable in the armchair and fill your pipe."

"Thanks," said Dunbar. "I will." He took out his pipe and reached out
a long arm for the tobacco jar. "I came to see if you could give me a
tip on a matter that has cropped up."

"Something in my line?" asked Stuart, a keen professional look coming
momentarily into his eyes.

"It's supposed to be a poison case, although I can't see it myself,"
answered the detective--to whom Keppel Stuart's unusual knowledge of
poisons had been of service in the past; "but if what I suspect is
true, it's a very big case all the same."

Laying down his pipe, which he had filled but not lighted, Inspector
Dunbar pulled out from the inside pocket of his tweed coat a bulging
note-book and extracted therefrom some small object wrapped up in
tissue paper. Unwrapping this object, he laid it upon the table.

"Tell me what that is, doctor," he said, "and I shall be obliged."

Stuart peered closely at that which lay before him. It was a piece of
curiously shaped gold, cunningly engraved in a most unusual way.
Rather less than an inch in length, it formed a crescent made up of
six oval segments joined one to another, the sixth terminating in a
curled point. The first and largest segment ended jaggedly where it