nts. He seemed to be approaching middle age; there were
faint traces of grey in his pointed beard and upward-twisted moustaches;
he carried his years, however, in very jaunty fashion, and his white
Homburg hat, ornamented with a blue ribbon, was set at a rakish angle on
the side of his close-cropped head. In his right eye he wore a
gold-rimmed monocle; just then he was bringing it to bear an the waitress
who stood between himself and his companion.

"You don't know the other man, either of you?" asked the chief suddenly.

Allerdyke shook his head, but Appleyard nodded.

"I know that chap by sight," he said. "I've seen him in the City--about
Threadneedle Street--two or three times of late. He's always very smartly
dressed--I took him for a foreigner of some sort."

The chief turned to his coffee.

"Well--never mind him," he said. "Pay no attention--so long as that man
is Van Koon, I'll watch him quietly. But you may be sure he has come here
on the same business that has brought us here. I--"

Allerdyke, whose sharp eyes were perpetually moving round the crowded
enclosure and the little groups which mingled outside it, suddenly nudged
the chief's elbow.

"Miss Slade!" he whispered. "And--Rayner!"

Appleyard had caught sight of his two fellow inmates of the Pompadour at
the very moment in which Allerdyke espied them. He slightly turned away
and bent his head; Allerdyke followed his example.

"You can't mistake them," he said to the chief. "I've described the man
to you--a hunchback. They're crossing through the crowd towards the
tea-house door."

"And they've gone in there," replied the chief in another minute.
"Um!--this is getting more mysterious than ever. I wish I could get a
word with some of our men who really know something! It seems to me--"

But at that moment Blindway came strolling along, his nose in the air,
his eyes fixed on the roofs of the houses outside the park, and he
quietly dropped a twisted scrap of paper at his superior's feet as he
passed. The chief picked it up, spread it out on the marble-topped table,
and read its message aloud to his companions.

"City men say the informant is here and will indicate the men to be
arrested in a few minutes."

The chief tore the scrap of paper into minute shreds and dropped them on
the grass.

"Things are almost at the crisis," he murmured with a smile. "It seems
that we, gentlemen, are to play the part of spectators. The next thing to
turn up--"