ad
suddenly the horrid fancy that poor Smythe's own iron child had struck
him down. Matter had rebelled, and these machines had killed their
master. But even so, what had they done with him?

"Eaten him?" said the nightmare at his ear; and he sickened for an
instant at the idea of rent, human remains absorbed and crushed into all
that acephalous clockwork.

He recovered his mental health by an emphatic effort, and said to
Flambeau, "Well, there it is. The poor fellow has evaporated like a
cloud and left a red streak on the floor. The tale does not belong to
this world."

"There is only one thing to be done," said Flambeau, "whether it belongs
to this world or the other. I must go down and talk to my friend."

They descended, passing the man with the pail, who again asseverated
that he had let no intruder pass, down to the commissionaire and the
hovering chestnut man, who rigidly reasserted their own watchfulness.
But when Angus looked round for his fourth confirmation he could not see
it, and called out with some nervousness, "Where is the policeman?"

"I beg your pardon," said Father Brown; "that is my fault. I just sent
him down the road to investigate something--that I just thought worth
investigating."

"Well, we want him back pretty soon," said Angus abruptly, "for the
wretched man upstairs has not only been murdered, but wiped out."

"How?" asked the priest.

"Father," said Flambeau, after a pause, "upon my soul I believe it is
more in your department than mine. No friend or foe has entered the
house, but Smythe is gone, as if stolen by the fairies. If that is not
supernatural, I--"

As he spoke they were all checked by an unusual sight; the big blue
policeman came round the corner of the crescent, running. He came
straight up to Brown.

"You're right, sir," he panted, "they've just found poor Mr. Smythe's
body in the canal down below."

Angus put his hand wildly to his head. "Did he run down and drown
himself?" he asked.

"He never came down, I'll swear," said the constable, "and he wasn't
drowned either, for he died of a great stab over the heart."

"And yet you saw no one enter?" said Flambeau in a grave voice.

"Let us walk down the road a little," said the priest.

As they reached the other end of the crescent he observed abruptly,
"Stupid of me! I forgot to ask the policeman something. I wonder if they
found a light brown sack."

"Why a light brown sack?" asked Angus, astonished.

"Bec