The Rookie season 5 trailer: Major death teased by return of old face ‘People will die'

The voiceover in the new trailer confirms: “Rosalind Dyer, a female serial killer, is going to complicate all of our lives.”

John and Rosalind curtly greet each other, before Rosalind promises: “People are gonna die. And you won’t be able to save them.”

The trailer then flashes several Rookie regulars – Rosalind’s potential victims – before the killer is seen getting her handcuffs removed and a female scream cries out.

In the next scene, John races through a corridor, exclaiming: “Rosalind, she’s trying to escape. We need to lock this place down!”