Brynne Larson and Tess and Savannah Scherkenback are all-American girls from Arizona, who enjoy martial arts and horse riding. But something sets them apart from most teenagers - they perform public exorcisms and often appear on TV chat shows.
Eighteen-year-old Brynne met sisters Tess and Savannah about eight years ago at a karate class.
"We just really hit it off," says Savannah, aged 21. "I don't know what happens but somehow you bond when you're punching one another and throwing knees. We were working out together, learning how to fight and how to defend ourselves and defend others."
They are now karate black belts, but because of their particular Christian beliefs, they have also decided to do battle - they say - against evil spirits or demons. They believe that these demons can possess a human being and cause suffering, depression or addiction.
"A demon can't just come into anybody whenever it chooses too, God doesn't allow that," says Brynne.