"Yours is a very interesting idea," said Quarles. "Do you happen to know
who Lady Rusholm was?"

"The daughter of a tea planter in Ceylon. Her social success here has
been very great, as you know."

"A very charming woman I should say," said the professor. "I saw her
once--not many months ago. She was distributing the prizes at a technical
institute in North London. I remember how well she spoke, and what an
exceedingly poor second the chairman was in spite of his being a Member
of Parliament. You have got a constable at The Lodge, I suppose?"

"Two. I have given instructions that no one is to be allowed in the room,
on any pretext whatever."

"Good. You and I will go there to-morrow. I'll be your assistant,
Wigan--say an expert in finger prints. I'll meet you outside The Lodge at
ten o'clock. There are so many clues in this case, the difficulty is to
know which one to follow, I must have a few quiet hours to decide."

I smiled. It was like Quarles to make such a statement, especially after
I had declared that criminals were becoming cleverer. Never were clues
more conspicuous by their absence, I imagine. I was, however, delighted
to have the professor's help. It was like old times.

The next morning I met Quarles in Queen's Square, and his appearance was
proof of his enthusiasm. He posed as rather a feeble, inquisitive old man
who could talk of nothing but finger prints and their significance. Sir
Arthur was evidently not impressed with his ability to solve any mystery.