“If in the first act you have hung a pistol on the wall, then in the following one it should be fired.” So Chekhov instructed playwrights, and so they are taught in drama schools everywhere.

But perhaps there should be a corollary: If you start your action with a bang, a gun had better follow.

In Alexis Scheer’s “Breaking the Story,” which opened on Tuesday at Second Stage Theater, the initial bang is an earsplitting doozy: an explosion that throws a war journalist and her videographer to the ground. Nor is it the first life-threatening attack that the journalist has experienced. We quickly learn that in her 20 years on the front lines, Marina (Maggie Siff) has been knocked down, knocked out, cut up and resewn many times over. A scar runs up the right side of her face like a cherry gummy worm.

Arresting and alarming though that is, it sets up an impossible comparison with the rest of the play, which, despite the director Jo Bonney’s efforts, is woefully light on dramatic ammunition. A rom-com is no match for a war.

That’s not just the play’s problem, but also Marina’s. The slim thread of story concerns her attempted retirement from conflict journalism and sudden engagement to the videographer, Bear (Louis Ozawa). But on the weekend of the wedding, it turns out she isn’t so sure she wants (or can even survive) the safe, domestic life she has spent her career avoiding. Danger was not merely a risk she took in choosing to be a war correspondent but the reason for the choice in the first place.

Thrill-seeking disguised as high-mindedness might be an interesting idea to explore, and indeed Donald Margulies’s “Time Stands Still,” about a war journalist likewise returning to regular life, explored it movingly in 2010. But Scheer’s framing, in which a flock of comic and undermining kibitzers descends for the wedding on Marina’s new estate in Wellesley, Mass., is too lightweight to support much content. For most of the play they treat Marina’s war-lust as an endearing character trait, already factored into their love for her.

It would therefore be nice if these characters brought with them, like house gifts, some conflict of their own, but their stories are almost entirely mild. Marina’s daughter (Gabrielle Policano) wants to take a gap year before college to further her singing career. Marina’s protégée (Tala Ashe) wants to dig up dirt for a podcast she’s producing. (The dirt, when finally dug, is anticlimactic.) Marina’s ex (Matthew Saldívar) halfheartedly wants to win her back. Marina’s best friend (Geneva Carr) wants to pull off a perfect last-minute wedding for her. Marina’s mother (Julie Halston) wants to have a good time.

A good time is not forthcoming. Over the course of the weekend, during which Marina will coincidentally be receiving a distinguished achievement award, she has terrifying flashbacks to the horrors she witnessed in various unspecified conflicts. (If you are prone to distress from loud noises and strobing flashes and footage of wartime destruction, you may find this material difficult.) That she is obviously suffering from post-traumatic stress does not seem to be of much concern to anyone; her daughter suggests she have some water.

The clash of tones arises from the intersection of choices that must have seemed apt on their own. One of the longer scenes in this shortish play finds the wedding party tasting cakes somehow conjured up overnight. The choices are at first ordinary — coconut, guava, chocolate — and a source of light comedy. But to dramatize Marina’s mental state, Scheer switches to surrealism as the scene resets several times, the cakes now bearing names like Dark Cheney and Cherry Hezbollah. Since only Marina notices this turn, the drama remains entirely interior.

Scheer’s breakout play, “My Dear Dead Drug Lord,” produced by Second Stage in 2019, demonstrated a vivid imagination and a gift for comedy that erupts from shifting subterranean emotions. An unsuccessful detour into musical theater — she adapted Emerald Fennell’s book for the Broadway incarnation of Andrew Lloyd Webber’s “Bad Cinderella” — has not entirely erased those qualities. When Marina warns Bear that she’s “a War Zone 10” but a “Real World 3,” it’s a good joke that’s also a tipoff to her concept of self-worth. But too much of the dialogue is either quippy or melodramatic, offering the shape of emotion but not the substance.

Except for Halston, who is incapable of not grabbing an audience, there’s little the cast can do to make this material feel full or fresh. Even Bonney, a director with miles of excellent productions to her credit — including “Mlima’s Tale” and “Cost of Living” — resorts to too many clichés. (The sound design, by Darron L West, and the projection design, by Elaine J. McCarthy, are especially obvious.) And a Hail Mary pass toward tragedy in the last moments of the play feels like an incomplete.

But just before that, Scheer does open an intriguing line of inquiry, as Marina, accepting her award, questions the values behind a model of journalism that valorizes danger to journalists. Her wounds, she tells us, have brought more attention to the suffering of the people she covers than they could ever receive on their own. That’s a perverse reward structure for everyone — including playwrights. Is tragedy, the story of suffering, worth it? Chekhov had no maxim for that; he called his plays comedies.

Breaking the Story
Through June 23 at Second Stage’s Tony Kiser Theater, Manhattan; 2st.com. Running time: 1 hour 20 minutes.