A scene from the 1973 film "The Exorcist" with Max Von Sydow is shown in this undated publicity photo.
Credits: REUTERS/Warner Home Video/Library of Congress/Handout
These are apparently a demon's worst nightmare.
Brynne Larson is 18 years old and enjoys horseback riding and shopping.
Savannah Scherkenback is a 20-year-old university student who works part-time in retail, while her 18-year-old sister Tess spends two hours each day studying the piano.
Together the girls from Phoenix, Ariz., are preacher Bob Larson's soldiers in a war raging between dark and the light.
Brynne cast out her first demon at age 13, she recalls.
And she'd like your child to follow her to the gates of Hell.
The three young girls travel as exorcists -- performing rite after rite, sometimes night after night.
"Evil is a reality -- everyone faces it," says Brynne.
"We have a choice to face it and fight or turn our back."
For Savannah, there are no doubts of demons.
The things they see, she says: "Defy human nature. To see a five-foot woman move four men around.
It's shocking and real."
The atmosphere in a room is charged when a demon appears, the girls say.
"There's almost a tangible presence of evil," Tess insists.
They are Larson's holy teen trinity.
"I am always present," cautions the preacher, who for 30 years has used public debates, radio and YouTube to spread his message of exorcising evil.
"(And) these girls know more about exorcism than any pastor or priest in North America."
You may have heard of Larson, or seen his work in the past week, as a video of him vanquishing a "homosexual sex demon" from a man during a church service spread like, well, hellfire.
Or maybe you spent $9.95 US to take his online "Demon Test" -- 21 questions to find out if you have the Devil or his minions in you.
But it's his plans for the future, including training young exorcists, that haven't gotten much attention.
His young demon-slayers run weekly Skype sessions with people from around the world, including one unnamed Alberta teen who's taking beginner exorcist lessons.
As well, next year the 68-year-old preacher wants to start an online exorcism academy, to teach young and old to cast out "snarling and fighting demons" -- something he says he's done 15,000 times.
His church is at the recruiting stage.
This week he travelled from Phoenix to Kansas City to San Diego -- the girls joining him this weekend -- and performed about 40 exorcisms along the way.
There's no lack of stop-overs ahead.
He estimates about 50% of the population has an evil presence lingering inside.
But welcoming teenagers to become demon warriors has invited worry and warnings.
Dr. Richard Gallagher, a professor of clinical psychiatry at New York Medical College and also on the faculty of the Columbia University Psychoanalytic Institute, has doubts about what the trio is doing.
Gallagher, an authority on exorcisms, believes those called to cast out evil should have many years of training and: "Show a great deal of sobriety, prudence and holiness.
"To just pick teenagers is ... a very dubious practice."
Father Gary Thomas, a Catholic priest at the Sacred Heart parish in Saratoga, Calif., is one of around 14 Vatican-certified exorcists in the U.S.
"What Rev. Larson is attempting is very dangerous when he involves teens in training them for this ministry," he explains. "This work requires a lot of spiritual maturity even for adults let alone younger people."
The public is often skeptical, he knows, but says he uses a team that includes a medical doctor, psychologist and psychiatrist in his discernment, to bring oversight to a serious process.
Rev. Larson counters he brings well trained fighters.
He also brings cameras.
His new reality show kicks off in about a week.
The first eight episodes are all his, but later, they will introduce his demon-fighting teens.
And they don't fear critics, with Savannah noting: "What we do is sensational by itself.
"Either way, there will always be those people who say that couldn't possibly be real.
"When you're there, they are undeniable."