Sam scowled and walked out.
Nevertheless....
Nothing to do with UFOs, of course. That was ridiculous.
But suppose there was a warp in the space-time continuum? Suppose there had once been another Ochterlonie Building, or some day in the future there was going to be another one, somewhere in New York? There wasn't another now, in any of the boroughs, or any other building with a name remotely like it; his research had already established that.
Sam went back to the Public Library. The building he knew had been erected in 1898. He consulted directories as far back as they went; there never had been one of the name before. Then a time-slip from the future?
That was hopeless, so far as he could do anything about it, so he cast about for another solution. How about a parallel world?
That could be, certainly: some accident by which mail for that other Ochterlonie Building, the seven-story one, had (maybe just once) arrived in the wrong dimension.
He couldn't do anything to prove or disprove that, either. What he needed was a break.
He got it.