“And I believe the starting point is that talk on the wire. That certainly is the work of an operator.
“Now, why is it heard only at this office?
“Say! Could it be on the loop? A cut-off arrangement on the station loop?
“I’ll go down and look into that right now,” declared Jack, and turning about, headed for the station.
The platforms and the big freight shed were alive with the bustle of the freight handlers, loading and unloading cars, trundling boxes and bales from one part of the platform to another and in and out of the big shed; and unnoticed, Jack discovered where the wires from the pole passed in under the roof. Entering the shed, he proceeded carefully to follow their course along the beams toward the telegraph room. He had almost reached the partition, and was beginning to think his conclusion perhaps too hastily drawn, when a few feet from the wall, where the light from an opposite window struck the roof, he caught two unmistakable gleams of copper. With a suppressed cry he made his way directly beneath, and at once saw that the insulation of both wires of the loop had been cut through.
“Right! I was right!” exclaimed Jack jubilantly beneath his breath. “And I can see in a minute how it’s done. Whoever it is, simply gets up there somehow, and ticks one wire against the other—and of course the instruments inside click as they are alternately cut off and cut on, and the rest of the line is not affected!
“Good! I’m on the trail.
“But what can be the object of it all?”
Jack turned to look about him, and as in answer the lettering of a nearby box caught his eye:
“VALUABLE! HANDLE WITH CARE!”