They originally appeared as contestants in Paranormal Challenge's 2nd episode. They won their competition.
Later, they assisted the GAC in an attempted experiment with the Winchester Mystery House. While Zak and Co. were at the mansion, Tri-State was operating at Bobby Mackey's Music World as the second part of the experiment while Mark and Debbie were at the Old Washoe Club. They experienced some odd things at Mackey's during the investigation.