Spoiler alert: final twist ends hit crime drama The Victim

It is the mystery over a fictional Edinburgh child killer which has gripped millions across the UK all week.

Viewers have been furiously debating the true identity of Eddie J Turner as the BBC One drama The Victim has become Britain’s latest hotly-debated “watercooler drama” over the last four nights.

But the final instalment in the story, which has revolved around the trial of Anna Dean (Kelly Macdonald) – a mother accused of conspiring to murder a man she believes killed her nine-year-old son – delivered a dramatic twist which left fans of the new Scottish crime and justice thriller reeling.

John Hannah starred opposite Macdonald as a detective determinedtoseekjusticefora Halloween attack on bus driver Craig Myers (James Harkness), who is married with a young daughter. The drama, which has had clear echoes of the 1993 James Bulger murder and the new identities given to his killers, has seen a host of possible suspects hotly debated on social media.

But – SPOILER ALERT – the hour-long finale saw Myers, who seemed to have been an innocent victim of mistaken identity, suddenly admit to the murder in a face-to-face meeting with the mother.

The Victim’s writer, Rob Williams, whose story was originally inspired by the polarising murder trial of South African Olympian Oscar Pistorius, revealed he made every effort to ensure the final reveal was kept as quiet as possible during the making of the series.

Speaking ahead of the broadcast of the final episode, Williams said: “The thing that changed was what happened to Craig at the end.

“I was also keen to leave open what would happen to him. We didn’t even go back to the court to see what happens with the sentencing of Anna. We felt that that wasn’t what it was really about.

“It was a legal thriller, but a human drama is what it really is. We tried to show that literally in the way that it plays out. It’s been a really great experience for me, trying to work out what I think about this subject and these characters.

“The reaction to the first three episodes has been absolutely phenomenal. It will be really interesting to see how people respond to the finale.

“I’m fascinated to find out whether people were surprised at the outcome. I’ve watched other shows and been disappointed at their finale. I really hope that’s not the case here.

“James Harkness’s performance throughout the series, but especially in the final episode, was extraordinary.” 0 Craig Myers (James Harkness), Anna Dean (Kelly Macdonald) and D.I. Steven Grover (John Hannah) in The Victim which has been showing on BBC1 this week