'I have long believed that loving a boyband brings with it a wealth of transferable skills, but I'd never imagined solving a murder would be one of them...'

Harri and her best friends worship Half Light - an internationally famous boyband. When frontman Frankie is arrested on suspicion of murdering his oldest friend Evan , Harri feels like her world's about to fall apart. But quickly she realises that she - and all the other Half Light superfans out there - know and understand much more about these boys than any detective ever could.

Now she's rallying a fangirl army to prove Frankie's innocence - and to show the world that you should never underestimate a teenage girl with a passion...