Brixton met us about eight o’clock that night in his now renovated den.  Apparently, even the little change from uncertainty to certainty so far had had a tonic effect on him.  I had, however, almost given up the illusion that it was possible for us to be even in the den without being watched by an unseen eye.  It seemed to me that to one who could conceive of talking through an incandescent lamp seeing, even through steel and masonry, was not impossible.

Kennedy had brought with him a rectangular box of oak, in one of the large faces of which were two square boles.  As he replaced the black camera-like box of the detectaphone with this oak box he remarked:  “This is an intercommunicating telephone arrangement of the detectaphone.  You see, it is more sensitive than anything of the sort ever made before.  The arrangement of these little square holes is such as to make them act as horns or magnifiers of a double receiver.  We can all hear at once what is going on by using this machine.”

We had not been waiting long before a peculiar noise seemed to issue from the detectaphone.  It was as though a door had been opened and shut hastily.  Some one had evidently entered the storeroom.  A voice called up the railroad station and asked for Michael Kronski, Count Wachtmann’s chauffeur.

“It is the voice I heard last night,” exclaimed Brixton.  “By the Lord Harry, do you know, it is Janeff the engineer who has charge of the steam heating, the electric bells, and everything of the sort around the place.  My own engineer—­I’ll land the fellow in jail before I’ll—­”

Kennedy raised his hand.  “Let us hear what he has to say,” remonstrated Craig calmly.  “I suppose you have wondered why I didn’t just go down there last night and grab the fellow.  Well, you see now.  It is my invariable rule to get the man highest up.  This fellow is only one tool.  Arrest him, and as likely as not we should allow the big criminal to escape.”

“Hello, Kronski!” came over the detectaphone.  “This is Janeff.  How are things going?”

Wachtmann’s chauffeur must have answered that everything was all right.

“You knew that they had discovered the poisoned wall-paper?” asked Janeff.

A long parley followed.  Finally, Janeff repeated what apparently had been his instructions.  “Now, let me see,” he said.  “You want me to stay here until the last minute so that I can overhear whether any alarm is given for her?  All right.  You’re sure it is the nine-o’clock train she is due on?  Very well.  I shall meet you at the ferry across the Hudson.  I’ll start from here as soon as I hear the train come in.  We’ll get the girl this time.  That will bring Brixton to terms sure.  You’re right.  Even if we fail this time, we’ll succeed later.  Don’t fail me.  I’ll be at the ferry as soon as I can get past the guards and join you.  There isn’t a chance of an alarm from the house.  I’ll cut all the wires the last thing before I leave.  Good-bye.”