See! Here is the key to it on my own ring.

There is no other.

I lost the mate to it myself not long after my installation here." The detective, working his way back around the pedestal, cast another glance up and down the gallery and over into the court.

Still no spying eye, save that of the officer opposite.
"We will leave that bow where it is for the present," he decided, "a secret between us three." And motioning for Correy to let the tapestry fall, he stood watching it settle into place, till it hung quite straight again, with its one edge close to the wall and the other sweeping the floor.

Had its weight been great enough to push the bow back again into its former place close against the door?
Yes.