Gateway to Elsewhere

This is the story of what happened to Tony Gregg after he had learned about the fourth dimension—or maybe it was the fifth or sixth—in a shishkebab restaurant in the Syrian quarter on lower East Broadway, New York.
He didn’t go to the restaurant originally to learn about the fourth dimension. His first visit was simply for shishkebab, which is a wonderful dish of lamb cubes skewered on small round sticks and cooked with an unlikely sauce containing grape leaves. It was quite accidental that he asked the owner of the restaurant about a coin that he—Tony—carried as a luck-piece.
Tony had bought it for a lucky charm in one of those tiny shops on side-streets in New York, where antique jewelry and ivory chessmen and similar wares are on display in the windows. He picked it out because it looked odd. His conscience—he had been raised with a very articulate conscience—reluctantly consented to the purchase because the coin was very heavy for its size and might be gold. (It certainly wasn’t a medal, and therefore had to be a coin.) It bore an inscription in conventionalized Arabic script on one side, and something on the other that looked like an elaborate throne without anybody sitting on it. But when Tony tried to look it up, there simply wasn’t any record in any numismatic catalogue of any coinage even resembling it.
One night—this was his first visit, not the later one when he learned about the fourth dimension—he went down on East Broadway for shishkebab, and it occurred to him to ask the Syrian restaurant-keeper what the Arabic inscription might say. The Syrian read it, frowned darkly, and told Tony that the coin was a ten-dirhim piece, that the inscription said it was a coin of Barkutand, that he had never heard of any place called Barkut. Neither had Tony. So Tony got a little curious about it, and the next day spent half an hour in the Fifth Avenue library trying to find out something about either the coin or the country it came from. But as far as the library was concerned, there wasn’t any place called Barkut. Never had been.