In “Poolman,” Chris Pine’s debut feature, he plays Darren, a distractible pool cleaner who becomes an amateur detective when he learns of a municipal conspiracy in Los Angeles. The sure-why-not plot, modeled on the California water grab in “Chinatown,” is less interesting than the charismatic cast that rambles along with Pine on his excellent adventure.

Pine’s yarn was savaged when it premiered at the Toronto International Film Festival last year, but the sour response is a bit like getting mad at a golden retriever for rolling around in the grass. A shaggy civic gadfly, Darren grandstands at City Council meetings and becomes so self-absorbed that he forgets what his girlfriend (Jennifer Jason Leigh) does for a living. His Jungian psychiatrist, Diane (Annette Bening), and her story-spouting filmmaker hubby, Jack (Danny DeVito), look after him like foster parents, while apparently overseeing some kind of movie about his life.

Darren is clued into the unnecessarily confusing water scheme by June (DeWanda Wise, glamorous and gorgeously costumed), who’s an assistant to his nemesis on the City Council (Stephen Tobolowsky). But the amateur sleuthing through Los Angeles landmarks — smartly shot on film by Matthew Jensen (“Wonder Woman”) — plays second fiddle to what’s really a collection of warm character sketches and mild eccentricities punctuated by meditative visions.

Pine wisely avoids winks to the audience. But he whiffs at making the mystery especially gripping, leaving one instead to savor the moments, like a note-perfect Bening calmly talking Pine’s befuddled pool man through his latest setback.

Poolman
Not rated. Running time: 1 hour 40 minutes. In theaters.