The series two conclusion saw lead Cassie Stuart, played by Nicola Walker, turn her back on a case she knew she’d solved and left audiences screaming: “How can you leave it there?”
Thankfully, Lang has revealed he hopes that won’t be the last we’ll see of the heroine.
"I hope not, I hope not," he told Radio Times. "I’d love to come back for another go. I’d like to do one more series because I want to square various circles with Cassie and Sunny."
He added: “I’ve certainly got another story to tell but it will be down to the audience and the broadcaster, whether they want it to come back.”
Unforgotten writer confirms plans for another series ITV drama
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Apple Tree Yard starring Emily Watson and Ben Chaplin, contained a number of sex scenes – including a traumatic rape scene
I’d like to do one more series
Unforgotten made no more than a ripple when it debuted on ITV in 2015 but soon became a sleeper success story as the nation was gripped by Stuart and DI Sunny Khan teaming up to solve the mystery behind a child’s brutal murder.
Its second series started afresh, with a new torturous case which saw three dead children who were later discovered to be the victims of child abuse.
“The idea for Unforgotten as a series came from the Stuart Hall case and then, for a number of reasons, I didn’t want to tackle sexual abuse in the first series," Lang explained.
"We came to writing this series at about the same time as there were some rather brilliant documentaries being made about some of the recent historic cases and some of the people who had been the victims of historic sexual abuse.
Unforgotten closed with an epic series two finale last night
Nicola Walker stars as DI Cassie Stuart in Unforgotten
"I was reading a lot about it and I also had personal experience of sexual abuse through friends and various family members. I knew a lot about it and what I wanted to write about, right from the beginning, which absolutely fitted into the structure of Unforgotten, is the sense of child sex abuse being something that destroys whole lives."
Viewers commended last night’s instalment as both “heartbreaking and heartmending”.
“What an astounding second series of #Unforgotten Brilliant acting, intelligent script and that finale, wow! Well done to all concerned,” wrote one particular delighted fan as another agreed: “Unforgotten. I doubt if there will be a better drama this year. Stunning performances, brilliant writing.”
A third cried: “The final of 'Unforgotten' is bloody incredible. Those speeches on the effect the abuse had on them were harrowingly real. And perfect end.”