Worlds of the Imperium by Keith Laumer

I was alone now, except for the ominous sphere behind the screen. I hoped for a caller, though. I went to the door which leaned aslant against the rough brick wall outside and unlatched it, maneuvered it into place and dropped the pins back in the hinges, then closed and relatched it.

I went back to the over-stuffed room, started looking through drawers, riffling through papers on the desk. I hoped for something -- something that might give me a hint of what Bale planned. I didn't find any hints, but I did find a long-barrelled twenty-two revolver, loaded. That helped. I hadn't given much thought to what I would do when Bale got here. I was in no condition to grapple with him; now I had a reasonable chance.