den--not a high wall. We
go in at a gate from the lane behind, and I think you should wait at
that gate, and put your men at hand. We mustn't go in as a crowd. The
rector had better go first, and you and I will follow on the opposite
side of the road."

So the procession was formed, and it was still some three minutes short
of eight o'clock when Hewitt and Plummer joined the clergyman at the
door in the garden wall behind Mason's house. The door was ajar as had
been promised in Mason's note. Leaving Plummer on guard without, Martin
Hewitt and the rector stepped as silently as possible through the little
kitchen garden and across a strip of lawn toward where a dull light
illuminated the conservatory, at the right-hand end of the house. The
door of the conservatory was ajar also, and this the rector pushed open.

"Miss Creswick!" the rector called, in a loud whisper. "Miss Creswick!"
And with that a girl appeared within.

"Oh, Mr. Potswood," she said, "I'm so glad you've come! I can't think
what's wrong with poor uncle! I'm afraid he must be going mad! He is
terrified at something, and he has been getting worse, till he could
hardly speak or walk. Dr. Lawson has been--about an hour ago, and since
then uncle has been much quieter, in his study."

They were entering the dimly-lighted drawing-room now. "Dr. Lawson?"
queried the rector. "Rather an unusual visitor, isn't he? How long has
he been gone?"

Miss Creswick flushed slightly through all her paleness and grief. "I
don't know," she said. "He let himself out, I fancy. He said he could
not stay long when he came, but I didn't hear him go; I have been
upstairs, and the servants are in the kitchen--they say uncle's mad, and
I'm really afraid he is!"

They left the drawing-room, and walked along the corridor and the hall
to the opposite side of the house, where the study lay. Miss Creswick
tapped gently at the door, but there was no answer. She tapped again,
louder, and then came the faint sound of a quick step on the carpet, and
then a slight scraping noise, as when a door is closed over a carpet it
will scarcely pass. "That's the window into the garden," said Miss
Creswick. "Why is he going out? Uncle! Uncle Jacob!"

But now the silence was wholly unbroken. Hewitt snatched quickly at the
door-handle. "Locked!" he said. "Come--the quickest way into the
garden!"

They ran out at the front door, and round toward the study window. It
was a French window, exactly at t