e the
murder jibe completely with Captain Strawn's theory of a gunman who had
trailed his quarry to the Miles home and shot him through the window.
The window was already open, but the screen had to be raised, too, and
Sprague's fingerprints had to be on the nickel catches by which the
screen curtain is raised or lowered. Of course Sprague had not touched
the screen----"

"Do you mean to say he lugged the corpse to the window and lifted it up
so that he could press the stiff fingers upon the nickel catches?"
Sanderson asked with a shudder. "What a fiend----"

"No," Dundee assured him. "That was unnecessary. He simply removed the
curtain screen, which is so designed that it can be taken down and put
up as easily as a window shade. He carried the screen--his own hands
protected by gloves, I suppose--to where Sprague's right hand lay _palm
upward_, on the floor, and pressed the thumb and forefinger against the
catches, making fingerprints all right, but they were reversed--as I
discovered when it occurred to me to examine the photographs of
Sprague's fingerprints in Carraway's office today. Miles could not turn
the stiff hand over without bruising the dead flesh; consequently the
print of the forefinger was on the catch where the thumb would normally
have left its mark--and vice versa.... Before I forget it, I should also
tell you that I found a master key hanging on the keyboard in the
butler's pantry. Big houses, with their many locks, are usually provided
with a master key, and Miles undoubtedly used that one to gain entrance
into my room after midnight Saturday morning."

"Where did you find the vise?" Strawn asked.

"In the tool chest right here, where he had also placed the reamer he
had bought. The vise probably belonged to Miles originally, but he was
taking no chances on anything's being found in his possession, provided
we tumbled to _how_ the two crimes were committed.... The reamer he must
have brought out here after he used it to enlarge the hole in my hot-air
register after midnight Sunday morning. It is possible he did his
cleaning up job here at the same time. It was safe enough to have lights
on, since the house is so isolated and there had been no guard here
since Thursday."

"Well--" Sanderson drew a deep breath. "He was a far cleverer man than
any of us suspected. The mechanical arrangements were absurdly easy to
rig up, in all three cases, but the _thinking_ of them----. It is a pity
Nita did not