Writer-director Sarah T. Schwab’s “A Stage of Twilight” is a somber melodrama about a couple facing an end-of-life decision with despair and as much grace as either can manage, under the circumstances.

It makes a fine showcase for its venerated, venerable leads — Karen Allen and William Sadler. But the plot only escapes from the tropes of this downbeat genre by shoehorning in tropes of another as we meet a young neighbor struggling to decide his own future while coping with family responsibilities and a romantic entanglement.

Schwab never overcomes the grim seriousness implicit in the subject matter, never allows a lighter moment and never quite brings us to tears, despite Allen’s best efforts.

Allen plays Cora, a small town librarian in rural New England (New Milford, Connecticut was the filming location), a woman whom we learn aspired to more than this in the opening scene, re-shelving books.

One was a novel Cora wrote years before, and she smiles when she notes that people have been checking it out and reading it.

Husband Barry (Sadler) shows up to surprise her with an anniversary dinner. Her laments of how “old and frumpy” she looks prompt a smirk and a twinkle. But his wasting cough tells us this won’t just be about love and devotion. He quickly learns his prognosis has changed. He has three months to live.

Barry runs through a range of reactions, “toe-tagging the pipes” of their aged farmhouse so that a future plumber will be able to make speedy repairs, buying a truckload of firewood. Barry’s got in mind to take care of Cora after he’s gone. But he decides “I don’t want your last memory of me to be of some old, sick man.” He’s got a plan for that, too.

As we pick up hints of their long-ago courtship and Cora’s distress at their differing approaches to this inevitable fate, their young neighbor Jimmy (Marlon Xavier) is starting to wonder if life on dad’s dairy farm is all there is. An ag-and-tech college might be in Jimmy’s future, if his stubborn father (Alfredo Narcisco) is willing to listen to reason and his smart kid’s ideas for improving their operation.

Jimmy’s local ties include the girlfriend (Emily Kratter) who has their entire future mapped out for them. Cora, perhaps wondering about her own path not taken, passes on suggestions that remind us of what fonts of helpful information librarians often are, even if one’s high school guidance counselor is no help.

The limited scope of the drama lapses into melodrama as Barry states his dogged intentions for “the end” and Jimmy visits college and promptly finds himself a potential girlfriend with wider horizons — not much wider, as every young woman he meets seems to appreciate his prospects for inheriting a big dairy farm.

The players are fine, but the mopey pace and somewhat generic “twists” to the plot make “A Stage of Twilight” — whose title promises a literariness the script never lives up to — something of a well-intentioned slog.

Rating: unrated, sex, fisticuffs

Cast: Karen Allen, William Sadler, Marlon Xavier, Emily Kratter, Alexander Flores and Alfredo Narcisco.

Credits: Scripted and directed by Sarah T. Schwab. A Cardinal Flix release on Amazon

Running time: 1:47