When Tarbell went out, Sprague quickly stripped his coat and went to work at his laboratory table. For some little time the man in the corner lay as he had been cast, and the worker at the table paid no attention to him. But a few minutes before Tarbell’s return, the red-faced man gasped, gurgled, and sat up to hold his head in his hands as one trying to remember what had happened to him. Presently he looked up, and after a long stare at the big figure of the man at the work table, he found his voice.

“Say, guv’ner, wot am I doin’ here?” he asked huskily.

Sprague, who was skilfully dropping a fuming yellow liquor from a glass-stoppered bottle into a beaker, replied without turning his head.

“If anybody should ask, I should say you are waiting for an officer to come and take you to jail.”

“Who, me? Wot have I been doin’?” queried the husky one, in the anxious rasp of a deeply aggrieved victim of circumstances.

“You’ve been shoving threatening letters under my door in the Hotel Topaz, for one thing,” said Sprague, still busy with his experiment.

“Who, me? My Gawd—just lissen to ’im!” wheezed the red-faced man, as if appealing to some third person invisible.

A silence followed during which the crouching man’s feet drew themselves by imperceptible fractions of an inch at a time into position for a tackling spring. Sprague did not look aside, but when the leg muscles of the man began to bulge as if testing themselves for the leap, the worker at the table spoke again.

“I shouldn’t try it if I were you. This stuff that I am fooling with is nitric acid, ninety-eight per cent. pure. If any of it should happen to get spilled on you, there wouldn’t be sweet oil enough in this town to put the fire out.”

“My Gawd!” gasped the red-faced one, suddenly sticking his feet out in front of him again; and just then Tarbell came in.