Director Nick Stock talks with actors before rehearsal of Horrorshow at the EMU Theatre.

Standing in a lit section of the black box theater, Carol Holstead holds a stage gun to the head of Todd Schwartz, both actors fully embracing their characters as they discuss a mysterious machine in the room.

This is their first time interacting with the machine, about a week in advance of the opening night of “Horrorshow VII: Tales of Monsters, Malevolence and Mercy.” The annual “Horrorshow” is a fall tradition of EMU Theatre, a group of volunteer actors, writers and directors from the community who put on several original plays throughout the year.

Opening night was originally scheduled for Oct. 25, but because of the unexpected death of one of the directors, David Butterfield, that week, the show will debut on Halloween, and run Friday and Saturday, all at 7:30 p.m.

The six-play horror show this year takes the audience to a dark, apocalyptic world where everyone is trying to survive, and the machine is supposed to be the solution. With only 11 members, the fewest people they’ve ever had in a production, Nick Stock wrote four of the plays, directs them, and is acting in a couple scenes as well.

“The horror show is more of what humans do when they are pressed in bad circumstances or under a lot of pressure,” Stock says.

Horrorshow actress Carol Holstead reacts during rehearsal at the EMU Theatre.

Although he wrote “Horrorshow” to be a world full of monsters, Stock chose to focus on the dialogue between characters.

“I feel like those are things that resonate with people, or at least with me when I watch plays and movies,” Stock says. For example, “It’s always cool to see special effects and Godzilla trashing through the city, but the story is never about Godzilla. It’s about the people on the ground who don’t know what to do when he is trashing through the city.”

Stock has been writing plays independently since he was 16, and without formal training, he likens the experience to working out a muscle. The more you work at it, whether it’s writing, directing or acting, he says, the easier and better it gets.

“It’s an activity I find very cathartic,” Stock says.

Amy Henderson and Dan Born wrote the other two plays in the show. This year’s collaborative effort turned out to be the most unified show the cast agreed they have ever seen in the history of EMU.

The cast remained quiet about the events that unfold over the 20-year span following some cataclysmic event, waiting until opening night to reveal the mystery. They couldn’t, however, keep themselves from talking about the personal artistic opportunities that EMU Theatre offers to any person interested in theater.

“It’s a really good place for people who maybe haven’t done a lot of theater and want to try it,” says EMU actress Carol Holstead, an associate professor at Kansas University who also has a master’s degree in theater. She doesn’t have time to do a full-blown production that rehearses for three hours a day, every day of the week. “Everyone in it has day jobs and are very talented.”

Holstead didn’t pursue theater as a career, but never wanted to give up on the adrenaline rush she feels every time she gets up on stage and experiences things in the skin of a new character.

“You really can forget about everything else going on in your life,” she says. “That’s the great part about theater. It’s a really intense form of concentration.”

The character development in EMU Theatre is unique in that the characters they are playing have been created out of thin air by cast colleagues. Holstead refers to this as “locally grown theater.”

“This is the one theater in Lawrence where actors get a chance to do that,” writer Born says. “We do mostly our own shows and we write ourselves, and chances are, an actor on stage at one our shows, that’s the first time that’s ever been done.”

And no one ever knows whether or not the show is good until the lights go off and they are on their way to the cast party — another thrill of performing a horror show written and practiced in a quick, two-month period.

“Because what we are doing is untested, none of these plays are put in front of an audience until we see how the show goes,” Schwartz says. “Somehow it all seems to work out.”