"No, no," said Sturgis, struggling faintly; "it cannot be both——and you——have——everything——to live for."
But the artist was now the stronger, and he succeeded in forcing his friend to inhale enough fresh air to restore his departing consciousness.
At length Sturgis, with returning strength, was about to renew the generous struggle with Sprague, when suddenly the place was ablaze with the glare of an electric light.
"He wants to see if his work is done," whispered Sturgis to his companion.
Then, observing that Sprague was again on the verge of asphyxiation, he continued hurriedly:
"Fill your lungs with air, quick!——quick, I tell you. Now drop and feign death. Do as I do."
Suiting the action to the word, Sturgis threw himself upon the stone floor, face downward, and lay motionless, his right hand grasping a revolver concealed beneath his body. Sprague, after a short breathing spell at the tube, followed his companion's example.
After a short interval there came a metallic click, which Sturgis recognized as the sound made by the opening of the slide in the panel of the door at the head of the stairs.
A moment—which seemed an eternity of suspense—followed, during which the prisoners felt, without being able to see, the cold gleam of the steely eyes of Murdock at the grating.
Would he enter? Would he suspect the ruse? Would the two men retain their grasp of consciousness and their strength long enough to make a last fight for life?