For a limited series to be whole, it first has to be broken. The “breaking” process — as in, breaking out the overall narrative and its individual episodes — is a crucial drama bubbling beneath the surface of every miniseries, or “novel for television” as it was once termed. When the breaking clicks, a limited series appears virtually seamless on arrival.

Mark Wolper, executive producer of History’s “Roots,” is one who swears by the classic dramatic principle of taking a character through a beginning, middle and end. He believes that that’s ideally served by “this thing of sitting down and knowing that at the end of eight hours, or 10 hours or 15 hours, you will have gone on an entire journey. You’ll have left, gone on a trip, had an amazing time and come home.”

But TV’s travel agents have a lot of planning to do, starting with the decision of how long the journey will be. At times it’s made quickly. Thanks to the 10 episodes of FX’s “Fargo” season one, all penned by creator Noah Hawley, he had confidence in that number’s rhythm and flow when handing out season two’s assignments.

David L. Wolper’s 1977 “Roots” ran 10 hours too, but son Mark felt “we tell stories faster now. ‘Let’s trim it a little,’ I said, ‘so I’m not forced to stretch things out.’” The symmetry of four two-hour segments was appealing to him.

On the other hand, “we could’ve done 12 hours, we could’ve done eight,” says Ryan Murphy, executive producer of FX’s “The People v. O.J. Simpson: American Crime Story.” “It’s just sitting down and figuring it out” during the outlining process, which led to the decision that “10 is the perfect number; these are the stories we want to tell.”

“American Crime” executive producer Michael McDonald had a similar experience: “We knew it would be between nine and 13 hours, but we were a little bit flexible. We all got together [on 10 hours] once we had our story and ABC had their schedule.”

Murphy, whose limited series experience also includes six seasons of “American Horror Story” and the upcoming “Feud,” says, “The story dictates [the number of episodes]. Always.”
“Feud” will run eight installments, while each “Horror Story” has veered between 12 and 13.

There’s less clarity about who dictated six hours for AMC’s “The Night Manager.” Director Susanne Bier came to treasure the potential in the miniseries for “giving the characters space to live and breathe.” But how much space?

She recalls John Le Carre’s sons, with experience in such matters, making “a quite smart estimate” long before adapter David Farr got involved. But when Farr is asked who chose six hours, he replies “I did, I suppose. The producers were great. They just said, ‘See how it feels.’” He envisioned a circular structure from Egypt into the heart of the supervillain’s criminal empire. A key sequence set in the mogul’s private study led back again to Egypt. “And this led to six feeling right, given that the study scene seemed to come in the middle of three.”

Farr’s comment illustrates the way miniseries writers segue quickly into the real “breaking”: the sometimes backbreaking work of deciding what will happen when. If you’re thinking of your series as “one big novel” (as McDonald characterizes “American Crime” creator John Ridley’s perspective), there can be real challenges in laying out chapters.

Hawley, for example, feels he needs to avoid a “late-middle problem” to which 10-episode series are prone: a letdown between exciting events midway and the expected thrills of the finale. “Things start to get a little slow,” he says.

To combat it, Hawley changed up the energy in “Fargo” episode seven, taking the protagonists out altogether. When they returned on the road in episode eight, “we kind of built to this two-hour movie at the end.”

Wolper and his “Roots” associates began by rereading Alex Haley’s book, watching the old series and digesting “a giant packet” of research on Africa and antebellum America. The producer also assembled a blue ribbon panel of 10 historians. “We asked each of them to give us a list of 10 things we don’t know about the period.” Then, he says, “in very classic old style, we put up a whiteboard and got out the dry-erase pens, and broke what we thought each night should be.”

“American Crime” was even more old-school in wielding 3×5 cards, color-coded by character. Ridley, aided by McDonald, worked out the original broad arc about teenage sexual assault and clashes between public and private schools. They then assembled a diverse writers field (“I think we had only one straight white male in the entire room,” McDonald says) for a five-week boot camp to knock out the outline.

That room, too, leaned on guest experts: “educators; rape counselors; gay male pro athletes who talked about their high school years.” After the entire series was outlined, Ridley was ready to assign episodes to individual writers and dissolve the room.

Once revised and polished by the showrunner, scripts tend to go into production with little concern for continued-next-week denouements. “We wrote without thinking of commercial breaks,” McDonald says. “We shot as a whole, and found the appropriate organic places to cut in the editing room.”

Nor are filmmakers worried if more breaking proves to be needed. “We shaped beats in editing,” Bier says. “Night Manager” episodes “are, to an extent, as written, but we moved scenes back and forth … to make sure the ‘cliffhangers’ and beginning and endings worked.” Editors made further adjustments to “The Night Manager” when one episode proved considerably longer than the other five, and when the serene Swiss Alps opening of episode one, following both novel and screenplay, proved “too soft, it didn’t grab,” in Bier’s words. Tense, action-filled scenes set in Cairo were substituted.

As virtually all practitioners point out, the limited series’ great advantage is its ability to bring events to an organic end. And by organic, they mean a conclusion dictated by the overarching theme. The “American Crime” principals are left at crossroads at fadeout, and appropriately so since none of their troubling issues admit to pat solutions. Murphy concedes, “We could’ve brought in O.J.’s life after the trial, his Las Vegas troubles,” but the journey to verdict “was all the story I was interested in telling.”

Similarly, while the original “Roots” extended into Reconstruction, the remake wraps up earlier. Says Wolper: “If your inciting incident is a free, intelligent, educated member of royalty being captured, where do you go in a multigenerational saga? Where that family walks away from capture. That happened with Emancipation. So we knew that, dramatically, that had to be our end.”
Murphy calls each new miniseries “always fresh and exciting, like a first date. It’s a medium of firsts, of beginnings.”

Hawley insists on knowing the outcome up front. “Endings have to be set up,” he points out. “The advantage of knowing what has to happen in the 10th hour, before you write the first hour, is that everything you do is in service to the end of the story.”

Farr’s visualizing the circular structure of “The Night Manager” figures here. So does previously unseen narrator Alex Haley (Laurence Fishburne) uniting with his ancestors’ spirits in the “Roots” finale.

“People vs. O.J.” co-creator Scott Alexander adds, “Obviously the show begins and ends with issues of race, and double standards, and institutional racism. So when we sold the project, Larry [Karaszewski] and I said, ‘We’re going to start with the Rodney King beating,’ to contextualize it all.”

Foreknowledge can have witty ramifications. In “Fargo” season one, Hawley knew he’d be using a bear trap in the final episode, “so every time you go to the brothers’ garage it’s there. It’s just hidden.” It’s also hanging next to a machine gun, which is what the audience thinks will be deployed by the end. “The imagery you lay in, and the themes of the piece, are all fully developed before you shoot, and really allow you to make a movie.” So for all the twists and turns a limited series can provide, it arrives home in one piece: “There’s a complete thought you’re expressing.”