VENTURA COUNTY WEEKEND : THEATER : NOTES : Popular Mysteries Keep the Audience Guessing : The classic ‘Mousetrap’ offers dinner with suspense; ‘Book of Murder’ gives patrons a chance to finger the culprit.

Two murder mysteries opened last weekend in Ventura County: Agatha Christie’s classic “The Mousetrap,” and the less-familiar “The Book of Murder” by Ron Cowen. The former, at the Marquie Dinner Theatre in Camarillo, includes a meal; the latter, at the Court Theater in Simi Valley, allows the audience to grill the suspects and help finger the culprit.

Christie’s play has been running in London, uninterrupted, for more than 40 years--that’s a classic by anybody’s standard. The story goes like this: It’s the first weekend of a new country inn, and the youngish owners are beset by an odd variety of customers, a severe snowstorm and word that a suspected murderer was last spotted heading in their direction.

Despite the presence of a policeman, assigned to protect the group, one of the guests is murdered. As each of the others is questioned, secrets are revealed and the finger of guilt points just about everywhere.

Even if you’ve seen the show before, watching Christie’s mind at work is worth the second viewing. Martin Horsey and Judy Weaver star as the newlywed owners, with Ron Ford, Marjorie Gaskell, Keith Hurt, Marina Reichl and Nels Jorgensen the visitors, and Darin Porter as Detective Sgt. Trotter.

The action moves smoothly under Terry Druxmen’s direction, and Ford is a casting director’s dream as the effete architect Christopher Wren.

In “The Book of Murder,” once-successful author Henry Aythecliff has run through his fortune and is now married to his third wife. Summoning the first two to a meeting, he announces that he’s about to publish his memoirs--and, if they pay him enough money, he’ll eliminate the chapters disclosing secrets they’d prefer remain secret.

When Henry is discovered dead, the list of suspects is obvious. Or is it? A police detective (Roxanne Diesel) is on hand to sort through the clues, but the audience is invited to question the suspects, examine the physical evidence and try to discover the murderer before the detective does.

It’s good fun, and the cast--also including Mikisha Harrison, Judie Kewish, Beth Murick and Ron Kewish-- neatly balances the skills of acting and (during the audience interrogation) improvisation.

* “The Mousetrap,” Thursday through Saturday nights, through Nov. 18 at the Marquis Dinner Theatre at Ottavio’s Banquet Facility, 340 Mobil Ave., Camarillo; $26 per person Thursday; $28 Friday, and $30 Saturday includes show, buffet dinner, nonalcoholic beverage, tax and gratuity. Discounts available for children and youth (12-19) all performances; seniors $24 on Thursdays only. For reservations or further information, call 484-9909.

* “The Book of Murder,” 8 p.m. Fridays and Saturdays; possibly Sunday at 2 p.m. at Court Theater, 3190 Cochran St., Simi Valley. All seats $7; for further information, call 522-0449.

Openings This Week: A special event surrounds one of the four (!) shows opening this weekend. Friday’s opening night performance of “Calamity and Wild Bill” at the Ojai Arts Center Theater will be preceded by a 6 p.m. barbecue dinner in the theater courtyard. Admission is $25; call 646-0117 for further information. This is a musical adaptation of a drama premiered at the Santa Paula Theater Center last year.

Casting Call: Auditions for “To Kill a Mockingbird” will be held Saturday at the Arts Council Center in Thousand Oaks. Director Georgeanne Lees is looking for actors of all ages; all who audition are to perform a monologue of their choice. The production will run weekends from Jan. 12-28 at the center. Call 499-4355 during business hours for an audition appointment.

The Moorpark Melodrama will hold auditions for “The Maltese Chicken,” Sunday at the company’s theater, 45 E. High St., Moorpark. Characters are, for the most part, exaggerated versions of those in the classic film “The Maltese Falcon,” plus a couple more hard-boiled (male and female) cops. Prospective cast members are asked to sign in at 9 a.m., prepared to sing (bring your own sheet music), dance and perform a cold reading from the script. Performance dates are Thursdays through Sundays, Jan. 12-Feb. 11. For further information, call 584-6300.