If you’re scared of the unknown, then Agatha Christie’s play “Ten Little Indians” will be a fitting end to your summer of theater-going in Maine.

The Acadia Repertory Theatre in Somesville, which is offering up Christie’s “Ten Little Indians” as the finale to its summer season, gives its audience a classic whodunit tale, featuring a lot of head scratching right up until the end when the murderer is finally revealed.

The play begins with two servants greeting the arrival of eight house guests, invited to spend the weekend at a solitary island inn off the coast of England by a mysterious host, U.N. Owen.

The storyline is set forth when a recorded voice accuses the guests of unpunished murders each has been involved in. One by one, those in the house — the 10 “Indians” — meet their own ends at the hands of this unknown murderer.

Director Ken Stack’s production begins with a lot of spark, as the actors feed off one another with a noticeable energy. Unfortunately, by the time the last two “Indians” are left standing, the spark has fizzled out.

Still, for 2 1/2 acts, “Ten Little Indians” is enjoyable.

While 10 actors on one stage might seem a bit cramped, Stack’s layout — courtesy of Brian Drohan’s construction — spreads things out enough to avoid any sardine effect. It also offers individual actors a chance to shine while others blend in with the background.

Keith Tralins, in the role of William Blore, has a commanding stage presence from his initial appearance until his final exit, and his scenes with Matthew Bernstein, as cocky world traveler Capt. Philip Lombard, are some of the play’s best and funniest moments.

Stephen McLaughlin, as Sir Lawrence Wargrave, grew nicely into his character, starting solidly as an inquisitive ex-judge and becoming quite convincing in his role as an old man. He walks, talks, and drinks coffee like an elderly person.

The attractive Catharine Slusar, in the role of Vera Claythorne, was very natural during her flow-of-the-story role. She seemed very flat during the times when she needed to reach inside and show her emotions, though.

Kathleen Lake, another 30-ish cast member playing the role of an elder, was dry, but realistic in her role as Emily Brent, the sinless Bible-reading guest who sits awaiting her fate.

Leslie D. Smith (Mrs. Rogers) and Stack (Fred Narracott) were both solid in their early, albeit cameo roles in Act I.

On the flip side, Ted Cancila, at times, seemed to over do it as the nervous Dr. Armstrong. Alan Gallant put forth an unsuccessful Tim Conway-ish effort, almost parodying the role of Gen. Mackenzie, and the English accents of Richard Blaine (Rogers) and Jon Ferreira (Anthony Marston) need some work.

Opening night’s show was marred by a few unexpected happenings — items falling off the stage and a gun that didn’t go off as expected — but considering the actors did not get to do a run-through on the stage until Monday, these errors were easily overlooked and, hopefully, will not happen again.

If Stack and company can keep that spark lit through the entire three acts, “Ten Little Indians” will be sure to please many.

“Ten Little Indians” will be performed 8:15 p.m. Tuesday-Sunday through Aug. 28 and 2:15 p.m. Aug. 14, 21, 28 at Acadia Repertory Theatre in Somesville. For tickets, call 244-7260.