It turns out that Babbitt Riordan is hosting a special party for author Zane Grey to celebrate the completion of his novel “The Call of the Canyon.” The best and brightest of Flagstaff have assembled to rub shoulders with the famed writer.

Suddenly, someone hits the floor and a call goes out for help. Enter Detective Richard Dick, who never met a dame he trusted or a murder he couldn’t solve.

This is the big setup for “The Call of the Weatherford,” a murder mystery dinner event at 6 p.m. on Saturday, May 20 at Charly’s Pub in the Weatherford Hotel. The mystery-comedy invites diners to participate with a cast of actors to help solve the crime.

The event is $50 a ticket and includes dinner served in four courses over the two-hour run time (alcohol, taxes and tip not included). It is as a fundraiser for Theatrikos Theater Company and Canyon Moon Theatre. All invitations must be pre-purchased by calling (928) 779-1919, ext. 430. Dressing in Roaring Twenties attire strongly encouraged.

The murder mystery is written by Mary Guaraldi of Canyon Moon. She has staged two other murder mystery dinners at the Weatherford that turned into crowd favorites, with the audience excited by this different kind of theatrical experience.

“It’s really a hybrid of theatre and improv,” Guaraldi said in a recent interview. “Each time the audience is involved in a different way … Each mystery I’m writing is based on something that happened at the Weatherford. This one is based on Zane Grey’s writing of ‘Call of the Canyon,’ and it plays a part in the murder mystery.”

From the outset of trying on the murder mystery theatre genre, Guaraldi knew that not every audience member would also want to participate in the action of the evening. So, she elected to stage it in a way that not everyone who attends has to be a part of it.

“We choose the people who become a part of it,” she said. “We have a spy who helps us choose them and we are looking for people who we think would enjoy being a part of this. It’s been a very successful way of doing things for us.”

As for the scripted portions of the program, Guaraldi invented the character of Detective Richard Dick to be the star. With the other parts, she explained that she writes for the actors she casts. “The actors like that because I can hear their voices and work with them,” she added.

Guaraldi, however, is keeping secrets about the number in the cast, the other characters and other details of the script.

For the people who have attended the past two murder mystery dinners, she said it’s no secret how much fun they’ve been.

“You have a wonderful evening with your friends and it really is a unique experience,” she said.