Happy Valley finally returns to BBC on New Year's Day, nearly seven years after its second series ended. And it's arrival back on screens has left many viewers asking the same question - what happened in the last series.
It was back in 2014 that millions of fans became gripped by the exploits of former Coronation Street actress Sarah Lancashire. As police sargeant Catherine Cawood, a role a million miles away from her Wetherfield alias Raquel, Sarah was at the centre of some serious drama as she found out that Tommy Lee Royce, the man who raped and impregnated her daughter and drove her to suicide, was being released from prison, with him then being involved in the kidnap of local businessman's daughter, Ann Gallagher.
Royce ended up back in prison and in Happy Valley series 2, he and Catherine had a fraught face to face showdown at his mother's funeral, after she was murdered, leading Catherine to be implicated in a string of killings and having to prove her innocence. Whilst trying to clear her name, she was tasked with investigate a string of killings, linked to human trafficking. However, her colleagues Detective Superintendent Andy Shepard and Detective Inspector Jodie Shackleton began suspicious that the fourth victim, Victoria Fleming, wasn't actually murdered by the serial killer, but somebody else.
