underground connection that I believe exists. It is still early in
the afternoon. I shall make a hasty trip to New York and return
after dinner. I should like to watch with you in the den this
evening."

"Very well," agreed Brixton. "I shall arrange to have you met at
the station and brought here as secretly as I can."

He sighed, as if admitting that he was no longer master of even
his own house.

Kennedy was silent during most of our return trip to New York. As
for myself, I was deeply mired in an attempt to fathom Wachtmann.
He baffled me. However, I felt that if there was indeed some
subtle, underground connection between some one inside and someone
outside Brixton's house, Craig would prepare an equally subtle
method of meeting it on his own account. Very little was said by
either of us on the journey up to the laboratory, or on the return
to Woodrock. I realised that there was very little excuse for a
commuter not to be well informed. I, at least, had plenty of time
to exhaust the newspapers I had bought.

Whether or not we returned without being observed, I did not know,
but at least we did find that the basement and dark storeroom were
deserted, as we cautiously made our way again it to the corner
where Craig had made his enigmatical discoveries of the afternoon.

While I held a pocket flashlight Craig was busy concealing another
instrument of his own in the little storeroom. It seemed to be a
little black disk about as big as a watch, with a number of