When foul play, backstabbing or murder is committed onstage, no one really needs to ask: "Whodunit?"

Two troupes -- Cloak & Dagger Dinner Theatre and Mayhem & Mystery -- have been guilty of such acts for years.

Their dinner-theater productions of comedic mysteries give audiences a good time and a moment in the spotlight.

"The interaction is a big part of the appeal," said Mark Sartor of Cloak & Dagger, director of the long-running You Only Die Twice.

He has also appeared with the troupe for 16 years, racking up more than 200 performances.

"Most people want to be a part of the show," he said. "If they don't, then they have fun watching others interact."

The older troupe, Cloak & Dagger, began 18 years ago as the Mystery Cafe in the Jai Lai restaurant.

Since 1996, the company has performed Fridays and Saturdays at the Morse Banquet & Conference Center.

Dublin residents Joe and Sally Rielly have attended productions regularly since the move.

"We joke around and have fun with the actors, whom we've gotten to know over the years," he said. "Plus, the cost is reasonable and the food is good."

"The actors pick on us," his wife added, "and they get Joe up there because he's a ham."

The Riellys, who also frequent community theaters, appreciate the interactive format as a lighthearted, participatory alternative to traditional theater.

"At a normal musical or play, you just sit there watching it," she said. "But at Cloak & Dagger, the minute you go in, the actors are standing there in costume, saying hello to you and taking you to your table."

Celebrating its 10th-

anniversary season, Mayhem & Mystery takes a slightly different approach: It doesn't use actors as waiters, and it usually employs only three to five players.

The goal is the same, though: to involve and entertain the audience.

"Because all the action happens right there around the dinner tables," producer Jerry Francis said, "people become a part of the show."

He joined his wife, Artistic Director Tamra Francis, in expanding Mayhem & Mystery to Columbus in 2004 after founding the troupe five years earlier in Dayton.

They come up with the scripts and co-star in the shows, which are also presented in Dayton, Lima and Middletown.

"After doing this for 10 years, we have a pretty good gauge about people's body language," he said. "If some don't want to participate, we can tell -- but many others do. Some will volunteer. Or you say, 'You'd be great for this,' and they'll smile and get up."

In a bit of a plot switch for the holidays, theft -- not murder -- propels I'll Be Home Shopping for Christmas.

Mrs. Francis plays Mrs. Claus, who -- tired of the clutter in her house -- sells leftover toys on the Home Steals and Deals Channel.

After inventory and an assistant vanish, the Clauses call in a detective.

The show, which features Mr. Francis as Santa Claus, continues all month at the Spaghetti Warehouse.

Often, volunteers have the most fun, Mrs. Francis said.

"We always try to get several audience members to stand up and get involved," she said. "In this home-shopping show, we get people to be our demonstrators and give them cue cards to read testimonials about the products."

At a recent performance, a boy piped up with a premature confession: "I did it."

Mrs. Francis responded gently but firmly to keep the story on track:

"We're not quite ready for that point yet, but we'll get back to you, and I may have to take you in for questioning."

Such built-in opportunities for interaction -- along with plausible plots, wacky characters and actors in multiple roles -- keep folks returning, Sartor said.

Perhaps the key ingredient in a successful show, though, is the attitude of the actors.

"If the cast has fun," he said, "then the audience has fun as well."

You Only Die Twice, which opened in May and will run through February, finds patrons arriving in the afterlife.

Miranda Hinton plays Roberta, who takes charge of purgatory.

"We have to be in character 110 percent of the time," Hinton said. "A lot of people perceive our scripts as light, silly comedy fluff, . . . but that's almost more challenging. You have to concentrate when the audience is yelling things out and doing things that traditional audiences don't do.

"Some people may never have wanted to be actors or decided not to pursue it, but coming to our shows gives them a chance to be theatrical and get their sillies out."

For many, the funniest moments occur when audience members audition to appear as a dog that belonged to a character in the show.

"We have them howl and bark," Sartor said. "The 'dog' inevitably steals the next scene.

"Sometimes they growl or sit up and beg. Once, when I played Lucky (as an understudy), a lady volunteer humped my leg. . . . The audience thought that was hysterical."

mgrossberg@dispatch.com