Robert Caro in Turn Every Page (Mott Hupfel/Sony Pictures Classics)

The documentary Turn Every Page centers on the 50-year working relationship between Pulitzer Prize–winning biographer Robert Caro and his editor Robert Gottlieb. Directed by Gottlieb’s daughter, Lizzie, it engages and entertains, and will certainly be catnip to a specific audience of hardcore writing nerds.

It is mostly a character study/celebration of the two Bobs, but it also points out how much the publishing industry has changed during the last half century. The hugely ambitious projects they worked on together would likely never be financed by a publisher today, and a biographer and editor would never reach such iconic status. It’s something of a love letter to a bygone era. It also gives viewers an idea of how much work goes into producing mammoth texts like Caro’s and provides rare insights into the editorial philosophy (and personal quirks) of Gottlieb, one of the most important American editors of the last 60 years.

The relationship between the Bobs produces spectacular results—their first collaboration, 1974’s The Power Broker, was an immediate commercial and critical success. Somehow, they were able to conjure a compulsively readable 1344-page tome about the civil servant Robert Moses. Then they collaborated on four bestsellers about Lyndon Baines Johnson—the fifth volume is currently in the works as their fans wait with bated breath. Caro is now 87, and Gottlieb is 91, but both are still physically and mentally spry, so this film feels like an attempt to capture both of them while they are still active and working in the (sadly likely) event that the concluding tome of their LBJ series never appears.

Despite their long, productive relationship, the Bobs aren’t necessarily best pals. Indeed, they have a tense working relationship, and are very different men. Caro is empirical and factual, somewhat stiff, very much the Princeton man. Gottlieb, though also the product of elite institutions, is a bit looser and has a wider cultural palette, open to kitschy, pop culture. (He has a poster of Lassie in his office, loves ballet, and collects hundreds of plastic purses.) This is the essence of their magical chemistry: Caro loves research, and Gottlieb understands how to transform Caro’s mountains of information into a cultural event that people will not only actually want to consume but will cherish.

How exactly does this alchemy take place? The film provides lots of hints, but the money shot, of the two Bobs actually making the sausage, is censored. This is the final scene, where they meet at the offices of Alfred A. Knopf to hash out Caro’s manuscript for the final LBJ book. We see Gottlieb edit it and Caro responding, but Caro requests that the sound be turned off because it is a private matter between the two. So, the director sets the scene to jazz music, and we watch them collaborate, which is a treat if you’re a fan, but also a strange line to draw—if you’re appearing in a documentary about your life and work, why would you cut out the absolute meat of it?

The running time is fairly evenly balanced between the two, but Gottlieb gets perhaps a bit more play, which is a good thing, because his life is more colorful than Caro’s, who, unsurprisingly for a man who has done such an unfathomable amount of research, lives a fairly ascetic life. For example, Gottlieb and his grandson walk through the Strand, New York City’s biggest bookstore, as the elder points out some of the iconic books he edited, such as Catch-22 by Joseph Heller (it still sells well even 61 years after publication), and tells his grandson how he came up with the title.

Apparently, the Bobs have had a legendary, decades-long war over something seemingly insignificant, about which neither man will concede an inch: semicolons. Caro uses them all the time, and Gottlieb, though open to them, believes flat-out that Caro uses them incorrectly (as well as too often). A brief scene highlights some examples of Caro’s semicolon use, and it seems to me that they are being used either incorrectly or unnecessarily when either a regular comma—or an em dash!—would suffice. I couldn’t help but think of Kurt Vonnegut’s quote: “Do not use semicolons…All they do is show you’ve been to college.” This kind of renegade spirit is what Gottlieb brought to Caro’s work, and though it has been certainly contentious at times, the fact that Caro is open to it is why his books are so special.

Part nostalgia, part nerd hero worship, Turn Every Page will delight fans of the written word.