The Belfast Maskers production of Agatha Christie’s classic murder mystery “The Mousetrap” open at 7 tonight, Thursday, Oct. 1 , with a special preview night price of $8. Strange things are afoot at Monkswell Manor, as neophyte innkeepers Molly and Giles contend with some very odd guests, a blinding snowstorm and the realization that they may be snowed in with a cold-blooded killer. The show has been a favorite of theater companies all over the world since it premiered in 1954, and audience member who have seen it before are asked to not reveal the secret of “who done it.” The Maskers’ production is directed by Angela Bonacasa, in her Maine directorial debut. She has choreographed a number of fights and stunts for the Maskers and other theater companies in Maine for years. The show runs for two weeks, Thursdays, Fridays and Saturdays at 7 p.m. and Sundays at 2 p.m. Tickets are available at The Fertile Mind, at the theater one hour before curtain, or by calling the box office at 338-9668; $10 for teens and $15 for all others.