“What are you going to do?”

“We can’t do anything just yet, but it will be dark by the time I get over to the laboratory and back and then we can do something.”

That night we started prowling over the back fences down the street.  Fortunately it was a very black night and Craig was careful not to use even the electric bull’s-eye which he had brought over from the laboratory together with some wire and telephone instruments.

As we crouched in the shadow of one of the fences, he remarked:  “Just as I expected; the telephone wires run along the tops of the fences.  Here’s where they run into 72—­that’s the beauty parlour.  These run into 70—­that’s the dope joint.  Then next comes the Montmartre itself, reaching all the way back as far as the lot extends.”

We had come up close to the backs of the houses by this time.  The shades were all drawn and the blinds were closed in both of them, so that we had really nothing to fear provided we kept quiet.  Besides the back yards looked unkempt, as if no one cared much about them.

Kennedy flashed the electric bull’s-eye momentarily on the wires.  They branched off from the back fence down the party fence to the houses, both sets on one fence.

“Good!” he exclaimed.  “It is better than I hoped.  The two sets go on up to the first floor together, then separate.  One set goes into the beauty parlour; the other into the dope joint.”

Craig had quietly climbed up on a shed over the basements of both the houses.  He was working quickly with all the dexterity of a lineman.  To two of the four wires he had attached one other.  Then to two others he attached another, all the connections being made at exactly corresponding points.

The next step was to lead these two newly connected wires to a window on the first floor of the house next to the Montmartre.  He fastened them lightly to the closed shutter, let himself down to the yard again and we beat a slow and careful retreat to our flat.

In one of the yards down near the corner, however, he paused.  Here was an iron box fastened to one of the fences, a switch box or something of the sort belonging to the telephone company.  To it were led all the wires from the various houses on the block and to each wire was fastened a little ticket on which was scrawled in indelible pencil the number of the house to which the wire ran.

Kennedy found the two pairs that ran to 70 and 72, cut in on them in the same way that he had done before and fastened two other wires, one to each pair.  This pair he led along and into the flat.

“I’ve fixed it,” he explained, “so that anyone who can get into that room on the back of the first floor of the dope joint can communicate with the outside very easily over the telephone, without being overheard, either.”

“How?” I asked completely mystified by the apparent simplicity of the proceeding.

“I have left two wires sticking on the outside shutter of that room,” he replied.  “All that anyone who gets into that room has to do is to open the window softly, reach out and secure them.  With them fastened to a transmitter which I have, he can talk to me in the flat around the corner and no one will ever know it.”