Kim Rosenstock’s “Tigers Be Still” is a play about the things that growl in the night — those unspoken fears that trip us into emotional detours.

This comedy about depression is told with a cheery exterior and warm heart in Boise Contemporary Theater’s production, which opened Saturday.

Sherry (Lina Chambers), caught in a bout of post-grad malaise, returns home when her shiny new master’s degree in art therapy fails to get her a job.

She finds herself unable to get out of bed — like her mother, who has confined herself to her room for months and communicates with her daughters only via telephone.

Eventually her sister Grace (Cassie Moloney) joins them in the house of depression after being spurned by her fiance, Troy.

Sherry snaps out of it when her mom calls in a favor from an old boyfriend, Joseph (Arthur Glen Hughes), the principal at the middle school. He hires Sherry to teach art and give therapy to his son Zack (Evan Sesek), who is having trouble dealing with his mother’s death.

And yes, a tiger has escaped from the local zoo. But the fear of a wild animal attack pales compared to the inner turmoil of these characters, with surprisingly frothy, lighthearted results.

The play itself feels like an HBO comedy — clever, funny and always winking at itself. Rosenstock also writes for TV (HBO’s “Girls” and Fox’s “New Girl”).

Director Matthew Cameron Clark and company pull together a fast-paced, lively production.

Long and lanky, Chambers turns in a delightful performance in her BCT debut as Sherry. She gives her a wide-eyed, wacky edge, a kind of cockeyed optimism that’s as unstoppable as a freight train. Yet she does it with a sincerity that centers her character as the heart of the play.

Moloney, who is new to BCT and Boise, is wonderfully charming and likable as Grace, who has made it as far as the couch with her bottle of Jack Daniel’s. Together with Chambers they create moments of loving clarity and tension that can happen with families.

Hughes — a longtime company member — gives one of his best performances as Joseph. He manages to bridge the line between sadness and putting on a good front with artful precision, pulling out wonderful moments of humanity.

Sesek gives Zack, whose tragedy is perhaps the most profound, a winning quality as he struggles with anger at the world and himself.

The flaw of the piece lies in the scale of its production. Michael Hartwell’s massive set fills the BCT performance space from wall to wall with a scale model of the town — houses, streets, trees and street lights — that represents the larger community. When characters move from one set to another, the house they’re in is illuminated.

Though beautifully crafted and impressive, it doesn’t add to or inform the play. The production is bigger than the play demands. That being said, the production doesn’t suffer overly much for it.

Raquel Davis’ subtle — and sometimes not so subtle — lighting helps keep the action focused on the characters. Tim Long’s sound design weaves the scenes together, with some clever musical choices.

All in all, it’s a fun and touching night at the theater.

Dana Oland: 377-6442, Twitter: @IDS_DanaOland