It was a grand and ambitious scheme, and after Scott Sherman reported, in The Nation, in late 2011, that the library's new president, Tony Marx, was taking steps to implement it, considerable anxiety was aroused among longtime users of the library, including me. I was afraid that the plan would compromise the library's research mission. At the time, the library believed that there were roughly 4.5 million books on site (today, now that the library has bar-coded all of them, administrators believe the correct number was closer to four million), and initially the plan was to lower that figure to somewhere between 1.5 million and two million. Almost every major research library has to store part of its collection remotely, but in this, as in all things, there must be proportion. It takes time to get a book from New Jersey into Manhattan, and if a researcher has to wait a day or two to see a new text some of the serendipity goes out of research. If a researcher's deadline is tomorrow, a book that he can't see until the day after is of no use to him. Other aspects of the plan worried me, too. I was saddened to think that a classic, century-old building was going to be radically altered, and I was unconvinced that the finances added up (by 2012, the cost estimate had jumped to three hundred million dollars), or that finances ruled out alternatives as decisively as the administrators were then arguing.

I was kept aware of the story as it developed, in part because Sherman is a friend of mine, as is the writer Charles Petersen, who was at work on an article about the plan, later published in n+1. Perhaps because I had held a fellowship at the library in 2002, and had been doing my research in the building since years before that, the library's administrators remained willing to talk with me, even after it became clear that I was a critic of the plan. In 2012, I wrote about the future of the library on my personal blog, sometimes at inordinate length, and I coördinated with other concerned scholars, including Stanley Katz, of Princeton, Joan Scott, of the Institute of Advanced Study, and the architect and historian Charles Warren.

In retrospect, the Marx administration's willingness to share information looks like an early sign of an institutional mind being kept open. Other such signs followed: in May, 2012, Marx took part in a public debate at the New School; then, in September, 2012, the library announced that an eight-million-dollar gift from Abby and Howard Milstein would make it possible to bring into service a second level of the Bryant Park storage facility, dug long ago but never used. This meant that the capacity of the underground storage would double, to three million books—a significant compromise. I still doubted the plan's financial soundness; I still wished that the building could be left intact; and I was unimpressed by Norman Foster's architectural sketches when they were revealed, in December, 2012. But I didn't think that the administration was likely to give any more ground, and I appreciated how far it had come. Because I had a novel that I needed to revise and then see into print, I decided to bow out of the debate.

Fortunately, Warren, Scott, Katz, and others continued to agitate, and they and other activists formed several new groups—including the Committee to Save the New York Public Library, Citizens Defending Libraries, and the Library Lovers' League—to protest the library's plans. Though I stopped following the story closely, I was aware that these groups were holding rallies on the library steps, making posters, passing out flyers, filing lawsuits, and meeting with the city's political leaders. I noticed when the Facebook page of Humans of New York featured a photograph of the activist Matthew Zadrożny eating his chicken lunch out of a tin on the library steps; in the caption, Zadrożny championed the preservation of the stacks. The picture went viral, making Zadrożny the closest thing the campaign got to a Jackie Onassis. From time to time, I got a call from one side or the other, but, from a distance, the two camps seemed to be at an impasse.

Last week's news, therefore, took me by surprise. On hearing it, I felt thankful that Marx's administration was willing to reconsider its position, and thankful that the activists had kept up the pressure for it to do so. A new third-party analysis, commissioned by the library, has confirmed that the cost estimates for reconfiguring the Forty-second Street building were indeed too low, and that the estimates for a stand-alone renovation of the mid-Manhattan branch were too high. "I heard the criticism, and we've learned from the criticism, which I think is absolutely appropriate for an institution that's publicly supported and public-serving," Marx said in a phone call on Friday afternoon. "When the third-party analysis made it clear that, actually, this was going to be much more difficult, much more expensive, and was not going to meet our program needs, then it was time to reëxamine other approaches."

I can think of two New York institutions—Cooper Union and the American Folk Art Museum—that have damaged themselves in recent years by barrelling ahead with imprudent construction projects, and, to me, Marx's change of mind seems remarkable, and worthy of praise. He is also strengthening the library's research mission with his fund-raising: he has been given four million dollars to endow a new position, chief humanities curator, and the single largest gift during his tenure thus far is a twenty-five-million-dollar donation, from the late Robert Wilson, for acquisitions and preservation at the research library.

Unfortunately, a bit of unfinished business may keep the library and its critics from an immediate truce. Though the library has agreed to preserve the stacks, it intends, at the moment, to leave them empty. The books that were once kept there were sent off site not long ago, in anticipation of the stacks' demise, and the administrators are now concerned that the stacks are too warm and too wet—paper decays more quickly under such conditions—and that they are not sufficiently fireproof. Marx told the Wall Street Journal that it would cost forty-six million dollars to upgrade the air-conditioning and fire-suppression systems in the stacks. Rather than putting money there, Marx would like to spend twenty-two million dollars (a figure that includes the eight-million-dollar gift from the Milsteins) to outfit the second level of Bryant Park's storage with not only protective outer layers, fire suppression, and air-conditioning but also compact shelving, which would increase the new level's capacity to 2.5 million books. The total storage capacity under Bryant Park would then be 3.7 million books—comparable, the library says, to the number of books immediately accessible to readers a couple of years ago, before all of this started. Today, with 1.2 million books under Bryant Park, eighty-five per cent of books requested are already on site, and the library estimates that when Bryant Park holds 3.7 million books the proportion will rise to ninety-three per cent.

As a matter of economics, the decision to leave the shelves empty may be eminently rational, but to many people it doesn't feel quite right, if only because it's hard to believe that the library's leaders would ever have chosen to empty the stacks if they hadn't been planning to knock them down. In my conversation with Marx, and in a follow-up e-mail exchange, I tried to kick the tires a little. I was told that the estimates of forty-six million dollars for the stacks and twenty-two million dollars for the Bryant Park facility were for insuring the same preservation conditions in both places—between sixty and sixty-five degrees Fahrenheit and forty-per-cent relative humidity. I asked whether the library will have to upgrade fire suppression in the stacks even if they're empty of books, and Marx replied that, in the absence of combustible material, the current sprinkler system is thought to be adequate. I asked how much of the forty-six-million-dollar estimate corresponded to fire suppression and how much to air-conditioning, but Marx wasn't able to say. It's worth noting that, at a press conference in December, 2012, he estimated that the cost of improving the stacks' air-conditioning alone would be between fifty and seventy-five million dollars. The new figure, forty-six million, is lower, and it covers fire suppression as well; Marx described it to me as a third-party estimate. In the Wall Street Journal, Jennifer Maloney reported that an upgrade of stacks at the Library of Congress has cost tens of millions of dollars, a comparable sum.

Charles Warren has called the building at Forty-second Street and Fifth Avenue "a machine for reading and thinking." There's an idea behind it: to bring books into the hands of readers as quickly as possible. The simple means is a set of elevators that raise books from the stacks into the reading rooms above. In my rough memory of how things used to be, a book from the stacks could be fetched in five to fifteen minutes, and a book from under Bryant Park in somewhere between twenty and forty-five. Is that difference in delivery speed worth spending forty-six million rather than twenty-two million? That is the question, and I'm afraid that I don't know the answer. Are empty stacks going to be the permanent and visible sign of the library's recent misadventure? It would be a pity if the stacks became no more than a museum piece, and I, for one, am hoping that someone comes up with another solution. A few years ago, the library spent fifty million dollars restoring its façade. It's painful to think that the money can't be found to repair its heart.

Caleb Crain is the author of the novel "Necessary Errors" and a contributor to the magazine.

Photograph: Ramin Talaie/Bloomberg/Getty