Sprague rushed to the speaking-tube and whistled long and loud, after which he placed his ear to the mouthpiece.
"I hear some one walking," he suddenly exclaimed.
The two men listened in breathless silence for an answering call.
"Well, gentlemen; what can I do for you?"
The words came in Murdock's voice.
Sprague's eyes met those of the reporter and saw that the last faint glimmer of hope was gone. In that swift and silent interchange of thought there was resignation to the inevitable doom and the final farewell of two brave hearts.
The spluttering candle gave its last flicker and went out, leaving the prisoners in utter darkness.
The room was rapidly filling with gas, and they were beginning to feel its effects.
"We can at least complete our task before we die," said Sturgis with grim determination.
"Our task!"