Devastating.

That word is a theme of the new play at the Unicorn, The Whale, and it’s a good one-word summary of the production itself. It’s a surprisingly intense tale that explores more issues than it would seem from hearing the plot description.

The show is about Charlie, a 600-pound man who is pretty much stuck in his home. He works as an online English teacher (so nobody has to see him) and he relies on a nurse friend to come over and help take care of him. When a Mormon missionary is visiting him, Charlie has a slight stroke. He decides he wants to get in contact with his estranged teenage daughter, even though her mother doesn’t approve.

Now, you might think that this is going to be a cheesy reconciliation story that tugs at the heartstrings. And you would be wrong. This is a tale both infuriating and depressing. Each of the characters has a backstory that slowly becomes known through the course of the play. Each of those backstories changes the way you see things.

This play could easily spiral out of control and become a train wreck if the actors weren’t able to handle the emotions of their characters. But this cast is impeccably constructed -- the five actors are five strong nails that keep this play tightly put together.

Manon Halliburton has the shortest role as the mother; even though she shows up late in the show, she is not drowned out as a minor character. She has no problem making herself (or her drama) noticed. Cinnamon Schultz has never played a bad role, and she plays the nurse that both helps Charlie -- and enables him. Schultz brings a guilty fury to her role that makes her a surprising pivot to the story. Jacob Aaron Cullum was last seen in the Unicorn’s production of Cock, so it was kind of jarring to see him play a Mormon missionary this time around. But he was able to make me forget his previous role, and he was mesmerizing as the young religious zealot looking for his own redemption.

The two other performances are the best I’ve seen in the last couple of seasons. Daria LeGrand plays the daughter with such brutal emotional sadism that she made me want to walk up on stage and slap her. The heartlessness that she must dig up to play her character so consistently makes my brain hurt.

Then there’s Phil Fiorini. Wow. Fiorini somehow finds in himself the exact character traits to make him both positive and pathetic. I wanted to give him a hug … and then slap him after I slapped his daughter.

A play called The Whale, about a morbidly obese man, will of course have a reference to Moby Dick. And sure, there are allusions to that novel in the play. But there is more than one whale in world literature, and playwright Samuel D. Hunter doesn’t give you the metaphor you might be expecting. Hunter is some kind of genius, to be able to take a morbidly manipulative idea and make it as sharp as razor wire. And then director Sidonie Garrett somehow has the vision to turn the script into something that can actually hurt you.

The Whale is a brilliantly written, awesomely acted story that upends a lot of what you expect to happen. It’s about family, health, religion, sexual orientation, death, and the possibility of saving people. Oh, and English. It’s also about English.

It is not always an easy play to watch. At times, I found myself looking halfway through my fingers because the scene was so awkward and mean. But it’s the best show of the Unicorn’s season so far, and it’s about a lot more than a fat man on a couch.

The Whale plays through March 27. For tickets, call 816-531-7529 or go to www.unicorntheatre.org.