at it
isn't just a nervous fancy? Your father really has changed toward you
lately?"

"Not only toward me, but to all the world beside!" she responded. "Now
that I look back, I can see that his present state of mind has been
coming on gradually for several months, but it was only a short time
ago that something occurred which seemed to bring the matter, whatever
it is, to a turning-point. I remember that it was just a few days
before you came--I mean, before I happened to see you over at Mrs.
Quinlan's."

She stopped abruptly, as if an arresting finger had been laid across
her lips, and after waiting a moment for her to continue, Morrow asked
quietly:

"What was it that occurred?"

"Father received a letter. It came one afternoon when I had returned
from the club earlier than usual. I took it from the postman myself,
and as father had not come home yet from the shop, I placed it beside
his plate at the supper table. I noticed the postmark--'Brooklyn'--but
it didn't make any particular impression upon me; it was only later,
when I saw how it affected my father, that I remembered, and wondered.
He had scarcely opened the envelope, when he rose, trembling so that
he could hardly stand, and coming into this room, he shut the door
after him. I waited as long as I could, but he did not return, and the
supper was getting cold, so I came to the door here. It was locked!
For the first time in his life, my father had locked himself in, from
me! He would not answer me at first, as I called to him, and I was
nearly frightened to death before he spoke. When he did, his voice
sounded so harsh and strained that I scarcely recognized it. He told
me that he didn't want anything to eat; he had some private business
to attend to, and I was not to wait up for him, but to go to bed when
I wished.

"I crept away, and went to my room at last, but I could not sleep. It
was nearly morning when Father went to bed, and his step was heavy and
dragging as he passed my door. His room is next to mine, and I heard
him tossing restlessly about--and once or twice I fancied that he
groaned as if in pain. He was up in the morning at his usual time, but
he looked ill and worn, as if he had aged years in that one night.
Neither of us mentioned the letter, then or at any subsequent time,
but he has never been the same man since."

"And the letter--you never saw it?" Morrow asked eagerly, his
detective instinct now thoroughly aroused. "You don't know