How do you stop a killer no one believes exists?

DS Kat Ballantyne wants to know why a perfect girl like Rosie Duggan would jump to her death from a multistorey car park.

Everyone is saying she took her own life. But Kat is unconvinced. Girls like Rosie—bright, popular, well adjusted, and with her whole life ahead of her—don’t fall from tall buildings.

Unless someone pushes them.

When a second student dies the same way, Kat is the only one asking the hard questions.

As she digs deeper, a disturbing pattern begins to emerge. With loyalties fracturing and powerful enemies circling, shocking DNA evidence leads to a surprising suspect.

But has Kat really found the killer? Or has she just been played?