n came unsteadily to his feet and blinked into the lane of
light made by the policeman's lantern. He was rather proud of his
disguise and the way in which it was passing scrutiny.

"All right, Macklin," he said in his natural voice. "It's Colonel
Berrington. Not quite the same sort of disguise that I tried to pass
into the Madi Halfa camp with when you were on guard that night. Still
it took you in, didn't it?"

"It did indeed, sir," Macklin said, not without admiration. "And might I
beg to ask what manner of game the Colonel of my old regiment is up to
in London at this hour?"

"We need not go into details, Macklin," Berrington said. "Regard me as
your senior officer for a moment, and answer my questions without
comment. As I told you yesterday, I am interested in that house
opposite. Have you found out anything?"

"Nothing worth speaking about, sir," Macklin replied. "They seem to be
just respectable people who have plenty of money and very few visitors.
Last night about half past eleven the old gentleman went out in a cab,
and came back about half past two with a friend who had a big box on the
top of the cab. That's all I can tell you."

"Ah, perhaps that is more important than it seems," Berrington muttered.
"Anything to-day?"

"Nothing to-day, sir. Oh, yes, there is. The parlourmaid reported to the
man who is doing day duty here this week that the house would be closed
till Saturday, and that the police were to keep an eye on the place at
night. Looks as if they've gone, sir."

Berrington swore quietly and under his breath. It seemed to him as if he
and Field were going to have their trouble for their pains. No. 100 was
not the kind of house where people are unduly economical on the score of
lights, and there was not one to be seen.

"I should like to go and have a prowl around," Berrington said, after a
pause. "I suppose if I did, I shouldn't have any officious policeman to
reckon with."

"Well, sir, I'm not quite sure," Macklin said dubiously. "Of course I
know you to be a gentleman as wouldn't do anything in the least wrong,
but there's my sergeant to consider. Still, as this is on my beat, no
other officer is likely to see you."

"Good," Berrington exclaimed. "What time will you be back here again?"

Macklin calculated that he would reach the same spot again an hour or so
later,--about eleven o'clock, to be exact. The hour tallied precisely
with the coming of Field, and in the meantime Berrington