I'd been weeks already on this case. A retired inventor named Robert Jakes, comfortable income and settled routine, just up and vanished. His niece was a friend who'd asked a favor.

 

I'd visited his usual haunts, which hadn't taken long; Jakes hadn't gone a mile from his apartment in twenty years. By now, I knew his routine by heart.

 

I'd been about to call my client and give up when Herbie Gottekind caught me at the office. He was waving a postcard.

 

"It's from him, I know it!"

 

It was a cheap souvenir card with Greetings From New York over the Brooklyn Bridge. The other side had Herbie's bookstore address and this: PxKN3.

 

"It's a chess move. Got to be code for something," said the book man excitedly.

 

"Did you fellows play?"

 

Gottekind nodded. "Most every day, but we never left it set up."

 

I looked it over carefully. "Pawn captures... Knight 3?"

 

"King knight 3, yes. Refers to the space, not the piece. Pawn takes knight, that would just be PxN. This would probably be one pawn capturing another. Descriptive notation can be vague."

 

I nodded, no wiser for his explanation. He read incomprehension in my face, then pulled a travel set out of his pocket and showed me until I got it.

 

"Oh," I said, then frowned. "Not sure it makes much... hmmm."

 

"You got an idea?"

 

"Part of one, maybe. You sell books, right? Remember one called 'City On A Grid'?"

 

He nodded. "Koeppel. History of Manhattan city planning. Good writer." He looked at me, then at the board, and his eyes grew wide. "It's a map reference!"

 

I'd already gone to the big office map, a massive wall hanging that had come with the place. "Yeah. So if we start at his apartment... King square..." I scowled. "We end up in the East River. Hmph."

 

"No, no. The address on the card, the bookshop, is white king." He muttered a bit, holding the board up, and then shouted in triumph, pointing. "Hague Street!"

 

"That's an old map. There's an apartment tower there now. Hasn't been a Hague Street in fifty years or more."

 

He looked at me owlishly through thick glasses. "Maybe we should go look anyway."

 

Why not?

 

* * *

 

It was a nice day, so we walked. On the way, we talked history, or rather Gottekind did and I listened. It was fascinating.

 

"New York is mostly built on older New York," he said at one point. "Go down ten feet, it's all service pipes and last century's basements. Ten feet more, you got abandoned subway lines and steam tunnels running every which way. It's a long way until you hit dirt, let me tell you. But the streets, those mostly stayed the same."

 

By now we'd reached our destination. "Along here's what used to be Cliff Street," he said. "So Hague should be... there." He pointed to a bollarded alleyway.

 

"Looks like they built over it when they put those towers up."

 

"No, that's the wrong angle. It would have run over this way, toward the bridge. Past those trees, you see the brick arch? It went under there at one point."

 

I craned my neck and stepped sideways, peering, then back. All at once it was there in front of me, rough pavement over old cobblestones, lined on both sides with faceless brownstones.

 

"Do you see that? Herbie?"

 

I looked around, but he was nowhere to be found. Neither was anything else. Two steps behind me, the road ended in a brick wall. Overhead, sunny sky had gone overcast.

 

Oh, well. Can't go back; might as well go forward.

 

"Mr. Jakes! Are you in here? Robert Jakes!"

 

I kept calling as I went. There were no doors on either side, and the one crossroad, which sported a sign reading Ferry Street, ended in two walls of mist. I pressed on.

 

Up ahead, the street angled under the bridge. I could hear traffic passing by overhead. The sound was muted, but comforting nonetheless.

 

As I passed under the brick arch, I saw reflected firelight. And there he stood, bulky in overcoat and homburg, warming his hands over a burning trash barrel.

 

"Mr. Jakes? People are looking for you, sir."

 

He grinned at me. "Figured they would. It would be rude of me to leave without saying goodbye."

 

I introduced myself, glancing at the curious landscape. "I'm still not sure where we are. Herbie Gottekind pointed me this way, but..."

 

He nodded. "The chess move. I'd thought I'd left enough breadcrumbs behind me, but when nobody came I started to get concerned. Still, all's well that ends well, and it was obscure enough to avoid government attention. Or whoever those men in the black suits work for."

 

I grunted agreement. I've met them, and can sympathize.

 

He handed me some papers. "There's a power of attorney in there for my niece, plus instructions. See that Herbie gets my library to dispose of; that should keep him busy. And now I'm off."

 

I was taken aback. "To?"

 

He grinned, then pulled out a strange device. "That cross-street behind you. Each direction leads to a different New York, a place where Hague Street still stands in one form or another. I've been working on this little gizmo for almost twenty years now, to let me slip through the cracks in reality — between realities, I should say."

 

"Sounds fascinating," I said. "But why dispose of everything? Won't you be coming back?"

 

He chuckled. "When you're dealing with holes in the fabric of everything, it's better to take care of things in advance, wouldn't you agree? Now, you'd best be getting back before I depart. This place may become unstable."

 

He didn't need to tell me twice.

 

Still, this left me with a problem: How was I going to explain all this? I turned back to ask, but he was already gone from sight.

 

Ah, well. I could always tell the truth...