This is a clever and chilling thriller for older teen readers and uses a documented phenomenon of mass hysteria as the basis for the story.

When Abigail, a cheerleader at high school, starts screaming in the middle of an exam, people find it funny. But as more girls start breaking into uncontrollable screaming fits, it's clear something is seriously wrong.

The authorities can't work out what's happening, nor can they stop it, but Clover and Brody, budding reporters, determine to find the answers.

Presenting their investigation on social media and in their school paper, they are in danger of making matters worse. But gradually they unearth the cause of the behaviour and it's a very dark reason indeed.

This is an incredible read. Plausible and compelling, it is a tremendous page-turner, and its reveal is troubling and challenging.