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More theatres should schedule shows with Halloween in mind. Ebenezer Scrooge and White Christmas make regular December appearances, but what about all the spooky, kooky death-and-frivolity shows that are just perfect for October?

The Constellation Theatre Company’s production of Little Shop of Horrors (which actually is going on until November 17) is not, of course, scary. But as a Halloweeny theatre experience, it’s an adorable bouquet of red-splattered roses. Tricks and treats are both found inside, along with “bloody, evil deeds,” campy monster mayhem, and a finale that feels like “Thriller” done as a PSA.

On a grey brick Skid Row — where the dashes of green weeds breaking through the cracks represent not life or optimism, but innocuously disguised menace — we find Mushnik’s Flower Shop. Drunks and street urchins linger by the trash cans. The eponymous shop owner (Robert John Biedermann) and his two put-upon assistants are on the verge of going out of business. Everything is so dreary that it must be sung about in aggressively cheerful Alan Menken melodies. But things turn around with the arrival (during a total solar eclipse, no less) of a strange, mysterious plant resembling a flytrap. It brings good luck and big business! Also: It eats people!

You probably know the story, but, as hapless loser and Audrey II caretaker Seymour, Christian Montgomery makes sure his character is constantly feeling his way along. Montgomery (side-splittingly funny in last year’s Melancholy Play) doesn’t make the mistake of trying to play this weirdo too naturally, and his voice carries Howard Ashman’s lyrics through some of their weaker spots. That definitely goes for Teresa Quigley Danskey as Audrey, too (err … Audrey as well!). Danskey plays a battered woman who thinks she deserves her abuse — in other words, an antique. But she never gives up on the character, and her performance of “Somewhere That’s Green” finds all its most ridiculous and sweet moments, skipping between them like a stone.

Directed by Nick Martin with musical direction by Walter “Bobby” McCoy, Little Shop is right up Constellation’s alley: dark but campy. And speaking of alleys, A.J. Guban’s squalor-meets-Sesame Street set acts like a series frames that the actors keep bursting out of, bringing to mind a graphic novel. Sarah Tundermann’s lights and Frank Labovitz’s costumes pay frolicsome tribute to the story’s B-movie past, while the puppets designed by Matthew Aldwin McGee almost steal the show.

Almost. But with an ensemble having this much fun, it’s everyone’s best night. Feed me more October theatre like this. Happy Halloween!