You have to admire Alan Ayckbourn. At 78 years old, after more than 80 plays, he’s undertaken a work of size, sweep and ambition. But with “The Divide,” a two-part, six-hour and aptly-titled epic premiering at the Edinburgh International Festival, he’s split his focus, straddling between prose and drama in a darkly imagined but uneven dystopian story. Think Dickens meets Atwood, with a touch of Bronte. While sometimes intriguing with some compelling performances, it is more often simply bloated and befuddling.

Here Ayckbourn returns to the sci-fi mode of earlier plays including “Henceforward” and “Comic Potential.” The play opens with a brief “lecture,” set many years in the future after “the fall of The Divide,” where the narrative premise is explained.

Back in the 22nd century, we are told, a devastating plague caused the near-collapse of the male population. Since infected women were blamed, the result was a new male authoritarian era, creating the geographical separation of the genders and making same-sex relationships the law of the land.

Birthed by women in the now-puritanical South through artificial insemination and raised by female couples, young males were apparently immune from infection until their mid-teens. At that point they were sent to the North to join the rest of the men, who are living a far more enjoyable and colorful life. (Must have golf, after all.)

Then the story proper begins, centering on a family in The South: young teen siblings Soween (Erin Doherty, terrific) and Elihu (Jake Davies, charming and earnest) and their ultra-conservative female parents, maw-maw Chayza (Finty Williams) and maw-paw Kets (Thusitha Jayasundera).

Soween faces a torturous adolescence with bad-girl school mates, a frustrated, curious mind and a heart yearning for love. But the real conflict kicks in late in the first half, when she and the artistically-inclined Elihu both fall for Giella (Weruche Opia), the daughter of two female “progressive” parents. A Romeo and Juliet story unfolds in the second part, in which a kiss can change a world.

First conceived as prose, the play is still tethered there, given its dependency on letters, e-mails, meeting minutes, diary entries and extensive first-person narrative. Still, Doherty’s Soween is so engaging, vulnerable, funny and heartbreaking that you sometimes forget that much of the time you’re watching a lavishly produced audiobook. And a stylish one, too, with striking minimalist designs by Laura Hopkins, with scene-enhancing lighting by David Plater and sound by Bobby Aitken. The production is further supplemented with music by Christopher Nightingale, played by a hidden four-piece orchestra and sung by a 20-plus member community chorus.

The handsomely produced show, which will run at London’s Old Vic starting in late January, is staged with taste and fluidity by director Annabel Bolton. But she can’t mask the many missteps of the script, and makes more than a few herself: Even at this long length, featured characters are wispily drawn; a significant character in the play’s beginning returns late in the second part for a clumsy plot point and cheap laughs; Giella is presented as too wily to fully earn the audience’s heart; a wedding party is too garish to believe.

Worst of all is a tonally jarring — not to mention needless and very long — epilogue, with a didactic Ted Talk sentiment killing whatever forgiveness an audience would have at what would seem the show’s natural conclusion, 15 minutes earlier. That’s a good place to start cutting and clarifying, if the show hopes to travel to U.S. shores. But perhaps that divide is just too great.

Edinburgh Review: Alan Ayckbourn’s ‘The Divide’

King’s Theatre Theatre, Edinburgh, Scotland; 1315 seats, £32 ($42) top. Oened Aug. 11, 2017; reviewed Aug. 11 and 12. Running time for both parts: <strong>6 HOURS</strong>.

  • Production: An Old Vic, Edinburgh International Festival, and Karl Sydow presentation of a play in two parts, with two acts each, by Alan Ayckbourn.
  • Crew: Directed by Annabel Bolton; designer, Laura Hopkins; composer, Christopher Nightingale; lighting, David Plater; sound, Bobby Aitken; video, Ash J. Woodward; movement, Lucy Hind; music director, Will Stuart; company stage manager, Debra Tidd.
  • Cast: Clare Burt, Jake Davies, Erin Doherty, Thusitha Jayasundera, Richard Katz, Sophie Melville, Clare Lawrence Moody, Weruche Opia, Martin Quinn, Letty Thomas, Sian Thomas and Finty Williams.