The plotline was a little convoluted at times, but I will forgive a lot for a brilliant premise, and boy, did this book have one.
So there was a mapmaker, General Drafting Corporation, which started some of the first road maps of New York State back at the beginning of travel by auto (i.e., prior to Triple A). They were generally cheap, purchased at the gas stations that were just coming into being, and were very carefully and meticulously researched. Before long, other larger firms (hello Rand McNally) were beginning to realize the value of these market, and were not above stealing the legwork from smaller firms. So as a defense against any copyright battles, General Drafting began inserting what was known as a phantom settlement, a tiny town on the map that never really existed. In the case of maps of larger urban areas, it would be perhaps a small room in a large public building that had never really been there. That way, if it showed up on the larger company’s map, the smaller firm could show that said company had not done their own research, but had copied theirs, intentional error and all. All of this, so far, is actually factual.
But shades of Brigadoon, and here is where it becomes fiction. A quintet of young cartographers, with young child in tow, rent a place in upstate New York, right after they graduate, with the idea of creating an interactive map. And to get to the house, they have an old road map with a phantom settlement called Agloe. And what they discover is that normally the phantom settlement remains bogus. But if you happen to have the old map open as you drive by where it isn’t. it is. You can drive down the now revealed road and find yourself in a completely physical town, fully stocked shops and all, except minus any people. Imagine the ramifications of that. As long as you there, it is absolutely real. Leave, and if you don’t have the map, it never existed.
From here on, we switch between the original group, and themselves twenty some years later, with the child, Nell, now grown up and trying to put the pieces together. Throw murder, infidelity, and arson into the mix and it becomes even more complicated. But, oh, that original idea. Loved it so much.