I had small time for thought.

Laying myself bodily against the door, I heaved and pressed with all my strength; but whether I was careless in my haste, or the cause was other, the lock did not give.

Instead the stool slipped, and I fell with a crash on the floor at the very moment the alarm reached the men below.
I remember that the crash of my unlucky fall seemed to release all the prisoned noises of the house.

A faint scream within the room was but a prelude, lost the next moment in the roar of dismay, the clatter of weapons, and volley of oaths and cries and curses which, rolling up from below, echoed hollowly about me, as the startled knaves rushed to their weapons, and charged across the flags and up the staircase.

I had space for one desperate effort.