How do you stop a killer no one believes exists?

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?