“Tell all the truth but tell it slant,” wrote Emily Dickinson, and writer/director Madeleine Olnek has taken her at her word.

Olnek’s film “Wild Nights With Emily” is a thing that should not work yet mostly does: a silly comedy seriously felt, about the Belle of Amherst’s lifelong romantic relationship with her sister-in-law, Susan Gilbert Dickinson, and about the stodgy propriety of those who conspired to hide that relationship from public view.

There may be more biographical basis to this tale than one might think, and it matters very much that “Wild Nights” has the approval of Harvard University Press and the Amherst College Special Collections archives to use Dickinson’s poems and passages from her letters.

At the same time, the movie stars comic actress Molly Shannon of “Saturday Night Live” fame as the poet, and indie filmmaker Olnek has gone on the record about her fondness for the prankish Web series “Drunk History.” Needless to say: Merchant Ivory, this ain’t.

And yet, the movie’s humor is built on genuine emotions and on the irony with which two women may have managed to live secretly out in the open.

“Wild Nights” bounces back and forth in time, and the early editing is pretty rough. We see the adult Emily (Shannon) and Susan (Susan Ziegler, TV’s “Days of Our Lives”) maintaining their next-door-neighbor affair under the societal cover of womanly friendship, and we see the two discovering their ardor for each other in their teenage years (Dana Melanie as Emily and Sasha Frolova as Susan). We also keep jumping forward to a turn-of-the-century lecture given by the primly smug Mabel Todd (Amy Seimetz), who has published much of Dickinson’s poetry and who claims to have known her well — even though they never met.

There are at least six points of view here: Mabel’s unreliable view of Emily; our increasingly suspicious view of Mabel; post-Civil War society’s view of women writers; the director’s view of her two subjects, and their respective views of each other.

Granted, that sounds like horse-carriage gridlock in downtown Amherst, but once you get your bearings, it plays with tart humor and widening empathy.