There’s a dead body in Somesville, and that means it’s Agatha Christie time again at the Acadia Repertory Theatre. This year’s installment for the annual Christie mystery is “Murder at the Vicarage,” which plays through Sept. 1. And it is murderous — in more ways than one.

First, of course, there is Col. Protheroe’s dead body, which is found hunched over in the vicarage one evening when he has come to settle some information about church funds. Protheroe had been an unpopular fellow in the village, and lots of people — including his ruthless wife — had a motive for putting a bullet through his head. The list of suspects is long: There’s the artist, the ingenue, the sickly curate, a very strange nephew, the vicar, his wife, and even Miss Marple herself.

Then there’s the script adapted by Moie Charles and Barbara Toy. At its best, an Agatha Christie play is light entertainment rather than literary phenomenon. But Charles and Toy have done nearly everything they can to make this story as bumpy and convoluted as possible. Following the plot is a major task, and so much of the information in the dialogue is extraneous that the effect is bound to be one of total confusion.

Finally, the script requires some deft juggling on the part of the director and actors. Ken Stack is a war horse in the murder-mystery genre, and he always manages to get the mood going in the right direction of quaint intrigue. Probably the only thing that could redeem this poorly written script would be a cast of completely superior actors, ones who can really take on the caricature of Christie’s characters and sustain that cartoonish tableau.

This is where Stack’s production falls short. That’s not to say there aren’t some nuggets of gold here. Ted Cancila is a strapping vicar. Laura Hodos, as a nutty neighbor, is a bounding delight. Stephen McLaughlin, as the inspector, is sweepingly forceful. Jennifer Barclay, as the maid, is an inviting and humorous presence — despite the distractingly garbled accent she’s using. And Stack, who plays the doctor, is as polished as ever in this role.

Alan Gallant, as the artist, is often dapper; and Leslie Smith, as the vicar’s wife, has sparkle, but never quite shines in the role.

Kathleen Lake plays Miss Marple and does a fine job transforming herself into a much older woman, but her lines are delivered with such a lack of energy and volume that her scenes never quite achieve the smart craftiness of her character’s well-known personality.

Much of the rest of the cast is rather young and not as expertly suited to take on a script that doesn’t give them much to work with. It would help immensely, too, if the performers would enunciate and speak up. It’s hard enough to follow the plot, let alone try to decipher a line delivered in a whisper.

The great thing about a Christie play, however, is that there’s enough that’s familiar to carry any production as a piece a fun fluff. And that’s the best part of this production. From Stack’s handsome set to Jodie Osgood’s elegant costumes and the puzzling whodunit aura, there’s some fun here, and that makes the bad writing and uneven acting bearable.

“Murder at the Vicarage” will be performed 2 p.m. Sunday and 8:15 p.m. Tuesday-Sunday through Sept. 1 at Acadia Repertory Theatre in Somesville. For tickets, call 244-7260.