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."