clutched at Walton for support.

"My God!"

Cairn, still holding on to the other, stooped over the discoloured
face. It had been a pretty face when warm life had tinted its curves;
now it was congested--awful; two heavy discolorations showed, one on
either side of the region of the larynx.

"What on earth is wrong with you?" demanded Walton.

"I thought," gasped Cairn, "for a moment, that I knew--"

"Really! I wish you did! We can't find out anything about her. Have a
good look."

"No," said Cairn, mastering himself with an effort--"a chance
resemblance, that's all." He wiped the beads of perspiration from his
forehead.

"You look jolly shaky," commented Walton. "Is she like someone you
know very well?"

"No, not at all, now that I come to consider the features; but it was
a shock at first. What on earth caused death?"

"Asphyxia," answered Walton shortly. "Can't you see?"

"Someone strangled her, and she was brought here too late?"

"Not at all, my dear chap; nobody strangled her. She was brought here
in a critical state four or five days ago by one of the slum priests
who keep us so busy. We diagnosed it as exhaustion from lack of
food--with other complications. But the case was doing quite well up
to last night; she was recovering strength. Then, at about one
o'clock, she sprang up in bed, and fell back choking. By the time the
nurse got to her it was all over."

"But the marks on her throat?"

Walton shrugged his shoulders.

"There they are! Our men are keenly interested. It's absolutely
unique. Young Shaw, who has a mania for the nervous system, sent a
long account up to Sime, who suffers from a similar form of
aberration."

"Yes; Sime 'phoned me."

"It's nothing to do with nerves," said Walton contemptuously. "Don't
ask me to explain it, but it's certainly no nerve case."

"One of the other patients--"

"My dear chap, the other patients were all fast asleep! The nurse was
at her table in the corner, and in full view of the bed the whole
time. I tell you no one touched her!"

"How long elapsed before the nurse got to her?"

"Possibly half a minute. But there is no means of learning when the
paroxysm commenced. The leaping up in bed probably marked the end and
not the beginning of the attack."

Cairn experienced a longing for the fresh air; it was as though some
evil cloud hovered around and about the poor unknown. Strange ideas,
horrible ideas, conjectures based upon imaginings all but