When an explosion rips through the chemistry lab at Dublin’s Raven’s Hill School and six girls are injured, the first thought is that it’s an experiment gone wrong. Then the Gardaí start investigating and declare it a potential bomb attack. But – if so – who was it targeting, and why? Ella, Becky, Maeve and Mackenzie are rushed to hospital, along with the injured Frankie and Sorcha, who team up with Jess to figure out what actually happened.

But what they discover is something more sinister than even they could have imagined …