Two real-life deaths haunt Torso, a new play by Keri Healey that opened last weekend and is already in the running for one of the best productions of the year. The first death was the playwright's sister, at age 38, from a misdiagnosed aortic aneurysm. (When she went to the emergency room, they sent her home.)

The second death was a murder allegedly committed by an old high-school friend of Healy's in 2008. The high-school friend and her brother conspired to kill their other brother over a minor financial dispute that metastasized into a blood feud.

The two stories curled around each other in Healey's mind, sharing a perverse sympathetic resonance. "Something about them was bugging me," she says. "I was missing my sister so much that it seemed unbelievable that someone who came from my same upbringing and background was implicated in a sibling murder."

So Healey did what writers often do with stories they can't shake—she wrote. She experimented with essays first, including a reading at the Hugo House literary series, before deciding to fictionalize the events in a play. "I'm not a journalist and I'm not interested in a biopic of what happened," she says. "But I found my emotional response." That response is theater noir, a moody, nuanced play and something of a quantum leap for Healey.

Her much-loved earlier scripts didn't have this much suspense—or this much blood. Parrot Fever (or, Lies I've Told in Chat Rooms) and Cherry Cherry Lemon involved people talking in rooms, usually about sex and relationships. Healy also wrote The IKEA Cycle, a series of short scenes staged guerrilla-style in the life-size dioramas of bedrooms, kitchens, and offices of IKEA. Hers is the kind of writing you don't notice as it reels you into a moment, before it lobs a precisely aimed grenade, whether it's a confession or a punch line. (As one of the women in Cherry Cherry Lemon says about having sex with a man with a small penis: "It's not like he was throwing a hot dog down a hallway—I Kegel!" That line, and the way it was positioned in the scene, used to reduce audiences to tears.)

Healey has been writing Torso for the last two years and says some credit for the complex, edge-of-your-seat structure is due to director David Bennett, who has directed My Fair Lady and Miss Saigon at the 5th Avenue Theatre. He nudged her toward more tension and dramatic action. In Torso, the dialogue happens in taxis, bars, depositions, police interrogations, and next to a post-murder bonfire—the actors' faces lit up by the flames.

The play supposedly happens over one night, but it also stretches like a telescope across years and states. As it begins, Daphne (Sarah Rudinoff) has just tried to board a plane back to Minnesota to track down her old friend Marlo (Susanna Burney), who is accused of murdering her own brother. But Daphne has had too many preflight cocktails and is told to leave by an airline employee. She pours herself into a taxi driven by Eddie (John Q. Smith), a big tough guy she just happened to have met on a disastrous online date a year earlier. In a flashback to their date, Eddie tipsily browbeats Daphne about the bar she's chosen for their first (and only) date: "Look around here," he says. "Everybody looks like they got a bus to catch. No one's relaxed." It's a familiar place, she finally admits, and safe. "Like I'm gonna hurt you," he huffs.

"Women get hurt. It's a fact of life," she says.

"Men get hurt, too."

"Statistically, less often than women do."

"A friend of mine got shot once," he protests.

"By a date?"

Back to the present: When Eddie gets her home, in Bitter Lake, Daphne realizes she doesn't have her keys, and they spend the night driving around looking for them, talking about her sister's death, the ways she fantasizes about avenging it, and the murder she's hoping to solve in Minnesota. Meanwhile, Marlo and her brother Dominick (Stephen Hando) and his wife, Tina (Emily Chisholm), begin to spin out over their frustrating lives—whether and how to commit fratricide and how to deal with the gory aftermath. (Revealing more details would spoil the thing—just go. You won't regret it.)

Torso pulls off two especially improbable feats. First, it introduces you to characters who kill a brother for money and shows how they get from being mad at him to murdering him. Healey says she was incredulous at first that people would kill a brother over a relatively small sum of money. (In the play, the siblings make a huge deal out of who gets possession of a Volkswagen Passat.) "But it was true," she says. "I guess I had some classist issues to deal with."

The second feat is to weave all of its crazy subjects—Daphne's grief and confusion, Eddie's checkered backstory (with its own arc of grief), the murder, the blood, the bonfire—into a play that feels whole but not pat, complete but not faking a resolution that isn't there. It's a stiff undertaking, but Torso succeeds, not least because of the emotional ballast that keeps the play stable—Daphne's grief over her sister and how it tweaks the way she deals with the world. Torso isn't explicitly about grief, but its complicated emotional logic is the play's blood and marrow. (A third feat, maybe more impressive than the other two, is avoiding lugubriousness—to do all this work with intelligence and comedy alongside the visceral tough stuff.)

"Grief is a profound contributor to who I am," Healey says, by way of explaining how she resisted tying a neat bow on Torso's complicated stories and emotions. "To lessen its impact or make it feel smaller would be to lessen my understanding of love and what matters about other people." The unique emotional undertones of grief, she says, are poorly understood by people who haven't been through them, but they inform Daphne and how she behaves—her fixation on exonerating her friend for the murder and on finding some kind of revenge for her sister's death. "I've spent a lot of time wanting to punch people," Healey says of the aftermath of her sister's death. "This culture of people who say 'It'll be okay' is wrong. It won't be okay. It will be there every day in some form. There's a lot less dwelling, but it's still there."

"The person I was before my sister's death—I accepted a lot of bullshit," she says, "in working relationships and that kind of thing. I was always the one who smoothed things over. It's like you walk through a fire with grief, like I'm not going to take your bullshit—I can take you on. I feel braver, less polite."

In Torso, Healey takes the gray, heavy, oozing mass of grief and uses it to give texture to what is, essentially, a suspense play: What will happen to Daphne and Eddie over one night? What will happen with the siblings in Minnesota? Why do people do terrible things? recommended