you."

"What is that?"

"Never mind now. Can you meet me at the Red House at five o'clock?"

"Yes. I will be there."

"Good. I don't hope for much. It's the strangest case I ever touched.
We are dealing with unusual people, not ordinary criminals."

"I agree."

"If there is any man in London who can see daylight through the
mystery I believe you are the man. Do you know on what I think the
whole thing turns?"

"On some undiscovered incident in Sir Marcus's past, beyond a doubt.
Probably an amorous adventure."

"You're wrong," said Gatton grimly. "It turns on the figure of the
green cat. Good-by. Five o'clock."

CHAPTER V

THE INTERRUPTED SUPPER

I arrived at the Red House before Inspector Gatton. A constable was on
duty at the gate and as I came up and paused he regarded me rather
doubtfully until I told him that I had an appointment with Gatton. I
stared up the drive towards the house. It was not, apparently, a very
old building, presenting some of the worst features of the
mid-Victorian period, and from whence it derived its name I could not
conjecture unless from the fact that the greater part of the facade
was overgrown with some kind of red creeper.

The half-moon formed by the crescent-shaped carriage-way and the wall
bordering the road was filled with rather unkempt shrubbery, laurels
and rhododendrons for the most part, from amid which arose several big
trees. In the blaze of the afternoon sun the place looked commonplace
enough with estate agents' bills pasted in the dirty windows, and it
was difficult to conceive that it had been the scene of the mysterious
crime of which at that hour all London was talking and which later was
to form a subject of debate throughout the civilized world.

Gatton joined me within a few minutes of my arrival. He was
accompanied by Constable Bolton with whom I had first visited the Red
House. Bolton was now in plain clothes, and he had that
fish-out-of-water appearance which characterizes the constable in
mufti. Indeed he looked rather dazed, and on arriving before the house
he removed his bowler and mopped his red face with a large
handkerchief, nodding to me as he did so.

"Good afternoon, sir; it was lucky you came along with me last night.
I thought it was a funny go and I was right, it seems."

"Quite right," said Gatton shortly, "and now here are the keys which
you returned to the depot this morning."

From his pocket the Inspector produced a ste