By Morris Panych. Directed by Ron Jenkins. A Vancouver Playhouse and Belfry Theatre coproduction. At the Playhouse on Thursday, March 31. Continues until April 16

A bunch of great lines don’t necessarily add up to a good play. In The Trespassers, the latest from Canadian playwright Morris Panych, almost all of the surprises come in the form of jokes. Most of the plot is easy to predict, and the thematic questions the play asks feel false because the playwright provides such easy answers. Fortunately, there are some winning performances in this production.

The central character, Lowell, is an eccentric 15-year-old. Lowell’s grandfather, Hardy, celebrates Lowell’s unique vision. Hardy also encourages Roxy, his whore-with-a-heart-of-gold girlfriend, to educate Lowell sexually. (All she does is show the delighted teenager her voluptuous body and let him touch her breast.) Hardy discourages religious belief and encourages bluffing at poker.

Lowell’s mom, Cash, entertains different views. She feels that Lowell’s diagnosis as borderline bipolar sets him apart, and she wants to ship him off to a special school. She is appalled by talk of sex, and she’s Christian.

Guess where the play’s sympathies lie.

There is a tiny bit of nuance in this. Hardy thinks Lowell should go off his meds, which is probably a bad idea, and there’s some complexity in the debate between unionist Hardy and his more free-enterprise daughter, Cash, but, thematically, The Trespassers plays in the shallow end. I won’t say much about the murder mystery that Panych weaves in, but the answer to its central question, “Why would you kill somebody you love?”, is achingly obvious in the context of the story.

Cash’s threat to send Lowell away is a standard sentimental trope, as is the idea of sneaking the aged Hardy out of the hospital when he falls ill.

Still, there are lots of belly laughs along the way. “Is this tea?” the appalled Roxy asks when Cash invites her in for a beverage. “It’s a bit late in the day.” The passage in which the dumbfounded Lowell cups Roxy’s boob is cheekily charming. And, in a surprisingly poetic passage, Lowell imagines his mother and his absent father making love.

Cliché characters are a problem, though. Hardy is a fountain of folksy wisdom: “We ought to welcome sadness. We ought to welcome death.” He feels like the playwright’s mouthpiece.

And, clearly, Roxy is a cliché. Fortunately, Jennifer Clement, who usually plays classier dames, lends charming vivacity to the role. And Natascha Girgis is terrific as Cash; Panych has some sympathy for his antagonist and Girgis takes full advantage, making her touchingly vulnerable. Unfortunately, Brian Dooley delivers all of Hardy’s lines in the same flatly declarative tone. But Amitai Marmorstein makes a wonderful Lowell. Marmorstein nails the character’s youth and the script’s comic rhythms. He’s responsive, playful, wily, weird—and moving: in my favourite detail from this production, Marmorstein’s Lowell absentmindedly plays with his grandfather’s beard, and you just know that Lowell has been doing that since he was tiny.

In Lowell, Panych has created a lovely character. But he hasn’t created a satisfying setting for him.