He was going a few stations down the line to investigate a rumour of a
suspicious person seen in that neighbourhood. It was a vague and
improbable rumour and the superintendent was setting out merely as a
matter of form, and to demonstrate his vigilance and almost abnormal
sense of duty. Darkness had already fallen for an hour or two when he
strode with dignified gait down the platform, exchanging a greeting with
an acquaintance or two, till he came to the front carriage of the train.
He threw open the door of the rear compartment, saw that it was empty,
and was just going to enter when glancing over his shoulder he perceived
his own cousin Mr. MacAlister upon the platform. Closing the door, he
stepped down again and greeted him.

Mr. MacAlister hailed him with even more than usual friendliness, and
after a few polite preliminaries drew him insidiously towards the far
side of the platform. An intelligent, inveterate and persevering
curiosity was Mr. MacAlister's dominating characteristic, and as soon as
he had got his distinguished kinsman out of earshot of the herd, he
inquired in a hushed voice:

"And what's doing aboot the murder noo, George?"

The superintendent pursed his lips and shook his head.

"Aye, man, yon's a proper puzzle," said he.

"But you'll have gotten a guid idea whae's din it by noo, George?" said
Mr. MacAlister persuasively.

"Weel," admitted the superintendent, "we maybe have our notions, but
there's no evidence yet, Robbie; that's the fair truth. As the fiscal
says, there's no evidence."

"I'd like fine to hae a crack wi' you aboot it, George," sighed Mr.
MacAlister. "I may tell you I've notions of ma own; no bad notions
either."

"Well," said the superintendent, moving off, "I'd have enjoyed a crack
myself if it wasna that I've got to be off by this train--"

"Man!" cried his kinsman, "I'm for off by her mysel'! Come on, we'll hae
our crack yet."

The tickets had already been taken and the doors were closed as the two
recrossed the platform.

"This carriage is empty," said the superintendent, and threw open the
door of the same compartment he had almost entered before.

But it was not empty now. In one of the further corners sat a man
wrapped in a dark coloured ulster. A black felt hat was drawn down over
his eyes, and his muffled face was resting on his hand. So much the
superintendent saw in the brief moment during which he stood at the open
door, and it struck him at once that