He laid his revolver down on the table where he could snatch it up again at a moment's notice.
"Behind a fireplace, eh ?" he muttered.

"What fireplace?
In what room ?" "I won't tell you!" The Doctor's voice was sullen.

He inched, gingerly, cautiously, toward the other side of the table.
"All right--I'll find it, you know." The detective's eyes turned swiftly back to the blue-print.

Experience should have taught him never to underrate an adversary, even of the Doctor's caliber, but long familiarity with danger can make the shrewdest careless.

For a moment, as he bent over the paper again, he was off guard.
The Doctor seized the moment with a savage promptitude and sprang.
There followed a silent, furious struggle between the two.