Heidi is your average everyday suburban young teenager who shares a household with her mother and father, brothers Joshua and Glen, sister Jane, and Grandma Ellie. Heidi has commenced first year at Gilmore Secondary College with her best mates, Chantel and Emma. She has a tomboyish persona, outgoing personality, hyperactive attitude, and she perceives herself as a slick city power girl that rocks the world. The latest playground gossip is Strathfield Disciplinary School, located in the country area, with a view to rectify the problematic attitudes of troublesome teenagers. And the rumors about Strathfield are unpleasant ones and rather gruesome. Heidi ends up being caught cheating on a maths test, and her brother Josh, including his mates Matt and Brad, are caught smoking marijuana. This leads to Heidi and Joshua (including their friends) being sent to Strathfield DS by their outraged parents. The gang of six unique characters embarks on a mystery journey at Strathfield. They unravel an interesting history to the building, including its main secret, which only Heidi and the gang dare to tread on. During their four-week stay at Strathfield DS, Heidi and the gang stumble across a shocking hidden secret in Mr. Barker's science experimental rooms, which questions who really requires set discipline-the Strathfield staff or its students?