ielle Engledue were
actually one and the same person. If they were, then I had made one
step towards the solution of the enigma.

I confess to utter bewilderment. My brain was still confused.
Sometimes my skull seemed wrapped in cotton wool. From a mere
unimportant person in the world of electrical engineering I had
suddenly become a man upon whom rested a great and criminal
responsibility!

In that huge, garish cafe, with its great arc lamps glowing though
night had not yet fallen, and with a noisy orchestra playing
selections from the latest crazes of music from the revues in London,
I sat with a perfectly open mind. I had been the victim of some
extremely clever plot. But of its motive, of its ramifications, or of
its conception, I had no knowledge. Even my wildest imagination was at
fault.

All I knew was that the sallow-faced De Gex--the millionaire who lived
up at the huge Villa Clementini--had plotted against the handsome
girl, and she had died in his wife's bedroom in Stretton Street.

"Well, Mr. Robertson, how can I find out anything more about Miss
Thurston? Give me your advice."

"I'll try and see what I can do," he said. "Perhaps I may be able to
get a glance at the mistress's address book. I have seen it. I'll
try."

"Yes--do!" I said very anxiously. "It means so very much to me."

"Why?"

I hesitated. My intention was to mislead both of my companions.

"Well," I said with a laugh, "the fact is, I--I'm very fond of her!"

Both men exchanged glances. Then they smiled, almost imperceptibly, I
know, but it struck them as humorous that I had fallen in love with
the daughter of a wealthy American.

"Of course I'm not yet certain whether she is the same lady," I went
on. "She may not be. But on calm consideration I believe she is. The
description you give of her is exact."

"Well," exclaimed the butler, "I'll see if I can get at the address
book. She keeps it in a drawer in her boudoir, which is usually
locked. But sometimes she leaves it open. At any rate, I'll see what I
can do and let you know."

I thanked him and told him that I was staying at the Savoy. Then I was
compelled to discuss with the estate-agent's clerk the pretended
renting of an apartment out by the Porta Romana, which, he said, was
vacant.

On the following day, in order to still sustain the deception, I went
and viewed the place, and found it really quite comfortable and very
reasonable. But, of course, I was compelled to e