There are many answers that spring to mind if you ask yourself, “What makes a good subject for a musical?” Love, cats, even Founding Fathers, but organ donation is probably not on your first draft of “Broadway-ready ideas.” Yet, the world premiere of “The Heart” at La Jolla Playhouse proves that the beat of a human heart can be as theatrical, funny, and devastatingly moving as anything else.

Based on Maylis de Kerangal’s acclaimed novel Réparer les Vivants (Mend the Living), the musical follows 24 suspenseful hours after the sudden death of 19-year-old surfer Simon Lamar (Zachary Noah Piser). His estranged parents (Kenita Miller and Jason Tam) must decide whether to donate his organs. Meanwhile, hospital staff hover in that tense limbo between procedure and compassion, while a woman named Claire (Heidi Blickenstaff) unknowingly parties on the eve of her second chance at life.

Zachary Noah Piser and Heidi Blickens taff in La Jolla Playhouse’s world-premiere musical The Heart; photo by Rich Soublet II.

The real star, however, is the heart itself, not Simon, not Claire, not even the many doctors and other characters that create this story. The musical tracks the organ’s journey like a hero’s quest, passing through grief, bureaucracy, and cold surgical precision toward its eventual rebirth, allowing the ensemble to play multiple roles in quick succession. The ensemble includes Heidi Blickenstaff, Lincoln Clauss, Bre Jackson, Max McKenna, Kenita Miller, Paul Alexander Nolan, Zachary Noah Piser, Wren Rivera, Jason Tam, along with understudies, Selena “Lena” Ceja, Cody Ingram, Brandon Keith Rogers, and Joy Yandell-Hall, to play multiple roles quickly.

Kait Kerrigan’s book balances the unthinkable with surprising humor, energy, and emotional touchpoints as each scene introduces a new layer to the process. Heidi Blickenstaff anchors the piece with multiple roles, balancing both darkly comic and raw vulnerability. Bre Jackson’s ICU nurse Cordelia delivers the powerhouse ballad “Right Now,” singing tenderly to Simon when no one else will.

Lincoln Clauss is excellent as Thomas, the hospital coordinator tasked with guiding Simon’s parents through the wrenching possibility of donation. His number “Quicksand” captures the impossible balance of the role: part advocate, part salesman, part grief counselor, and entirely human. The song lays bare the tension of needing something that only raw loss can provide, and Clauss handles it with nuance rather than force.

The cast of La Jolla Playhouse’s world-premiere musical The Heart; photo by Rich Soublet II.

The ensemble excels, from Wren Rivera’s quick-witted donor registry clerk who treats finding potential recipients as a game-ified life-or-death adventure quest through data to Paul Alexander Nolan’s swaggering transplant surgeon. Miller and Tam chart the impossible journey from shock to surrender with aching humanity.

Anne and Ian Eisendrath’s electronic-infused score is equally ambitious. At its best, it pulses with urgency, blending the rhythmic beeps of hospital monitors with the crash of ocean waves and the throb of a nightclub. The opening “Strike the Match” drops us into Simon’s surfer-DJ world, and numbers like “Dawn Patrol,” a father-son surfing duet, are beautifully bittersweet. At times, though, the score retreats into safer pop-musical territory, leaving me wishing for more of those immersive EDM soundscapes that turn the theater into a rave-tinged ICU.

Jason Tam(left) and Zachary Noah in La Jolla Playhouse’s world-premiere musical The Heart; photo by Rich Soublet II.

Christopher Ashley’s direction keeps the action taut, but it’s Mandy Moore’s choreography that really makes the stage feel alive. She moves the actors constantly with doctors rushing, nurses crossing paths, and parents circling each other in grief. The effect is both clinical and overwhelming: the hospital never stops moving, even as time seems to slow for those making impossible decisions. It’s a clever physical metaphor for how the world keeps spinning while someone’s life is upended.

Performers swirl across Robert Brill’s sleek, cold set, moving items in and out along with performers as scenes quickly blend into one another. Video projections by Lucy Mackinnon, which shine with pixelated ocean waves and a giant beating heart, were breathtaking. In contrast, other inserts, like a too-cutesy video game (players collect hearts), felt like filler. Lighting designer Amanda Zieve deserves credit for using color and shadow to underscore the piece’s emotional contrasts with warm family intimacy one moment, and a stark surgical glare the next.

For all its ingenuity, “The Heart” has some things that would benefit from being recalibrated. While the show runs a brisk 80 minutes, some characters like Simon’s DJ girlfriend Juliette (Max McKenna) feel sketched rather than fully fleshed out, and Simon himself remains mostly a mystery, which slightly blunts the emotional impact of his loss. Their time together on stage is too short to really get much detail about them as a couple.

Perhaps that’s fitting, since this isn’t just Simon’s story. It’s about the organ that brings renewed hope for life to strangers, and the ripple effect of choices made in impossible hours. “You only get one wave,” Simon’s father tells him. “So ride the wave and welcome the dawn.”

At La Jolla Playhouse through October 5th, “The Heart” rides its wave with courage, empathy, and a beat that stays with you long after the curtain falls.