Trial & Retribution — Season 12

Siren (Part 1): A car drives an ambulance off the road, killing Sebastian Cole, and wounding his famous fiance, Imogen Buller-Turi. The tabloid-covered murder becomes increasingly intricate as Walker and Connor explore its connection to international drug trafficking.

Siren (Part 2): Walker forces DCI Connor to team up with McGill and his squad in the hopes of expediting the murder investigation. Connor's earlier mistake ratchets up the tension as the unit races to anticipate Imogen's actions.

Ghost Train (Part 1): A teenager's fatal fall from a Ferris wheel initially seems to be an unfortunate accident. DCI Connor quickly realizes that to uncover the muddled truth behind the death, she must confront the carnival's mystic owners, including Satchel's fortune-telling aunt, Tess.

Ghost Train (Part 2): The arrest of Pavel yields unsatisfactory results, forcing Walker and Connor to continue searching for the motives behind the growing number of crimes. As they do, the line between criminal and victim blurs.

Shooter (Part 1): When a jewelry robbery goes awry, the notorious Bilkin family is put on trial for murder. After Satchel bungles his testimony, he must deal with Walker's frustration and the intense scrutiny placed on his personal life.

Shooter (Part 2): Walker's obsession with Bilkin family irks Connor, who questions the purpose of the investigation. Jamie enlightens Connor with information about the romantic life of Barry Bilkin, intensifying speculation about the family and its emerging issues.