snatched her wrist. "Why
did you do that?"

Kitty remained mute. "Answer!"--with a cruel twist.

"You hurt!" she gasped. Anything to gain time. She tried to break away.

"Why did you do that?"

"I was going to thrust it through a window to attract attention. It was
too heavy."

This explanation was within bounds of reason. It is possible that
Karlov--who had merely come up with a fresh candle--would have departed
but for a peculiarly grim burst of humour on the part of Fate.

Tap--tap--tap? inquired the unsuspecting man on the roof--exactly to
Kitty like some innocent, inquisitive child embarrassing the family
before company.

Karlov flung her aside roughly, stepped under the trap, and cupped an
ear. He required no explanations from Kitty, who shrank to the wall and
remained pinned there by terror. Karlov's intuition was keen. Men on
the roof held but one significance. The house was surrounded by Federal
agents. For a space he wavered between two desires, the political and
the private vengeance.

A call down the stairs, and five minutes afterward there would be
nothing on the spot but a jumble of smoking wood and brick. But not to
see them die!

His subsequent acts, cold and methodical, fascinated Kitty. He took a
step toward her. The scream died in her throat. But he did not go beyond
that step. The picture of her terror decided his future actions. He
would see them die, here, with the girl looking on. A full measure. Well
enough he knew who were digging away the cement of the trap. What gave
lodgment to this conviction he did not bother to analyze. The man he had
not yet seen, who had balked him, now here, now there, from that first
night; and who but the last of that branch of the hated house should be
with him? To rend, batter, crush, kill! If he were bound for hell, to
go there with the satisfaction of knowing that his private vengeance
had been cancelled. The full reckoning for Anna's degradation: Stefani
Gregor, broken and dying, and all the others dead!

He would shoot them as they dropped through the trap. Not to kill, but
to maim, render helpless; then he would taunt them and grind his heels
in their faces. Up there, the two he most hated of all living men!

First he restored Kitty's barricade--to keep assistance from entering
before his work was completed. The butt of the first plank he pushed
under the door knob. The other planks he laid flat, end to end, with the
butt of the last snug against