Unassuming UK star Olivia Colman back in 'Broadchurch' 2.0

LONDON (AP) - The laws of television decree that a show that's both a critical hit and a ratings success must return to our screens. The laws of crime thrillers say that once you know whodunit, the case is closed.

That's why some viewers were surprised to learn there would be a season two of the BBC's murder mystery series "Broadchurch" - and why the cast was initially skeptical, too.

"You want to make sure it's being faithful to the thing that you love," said Olivia Colman, who plays detective Ellie Miller alongside David Tennant's investigator Alec Hardy.

"Most of the cast thought, 'It was great. I don't know if I want to do it again.' And then Chris (Chibnall, the show's writer) talked us through the idea of the second one. And we all said 'Oh yeah. OK. Lovely. Count us in.'"

The second episode of season two airs Wednesday on BBC America. The first eight-part series, which ran in Britain in 2013 to huge acclaim, showed how the murder of an 11-year-old boy devastated his family and shook their picturesque seaside town.

(The series was remade by Fox as "Gracepoint," with Tennant reprising his detective role in an American accent.)

"Broadchurch" 1.0 was full of rich performances, particularly from Jodie Whittaker and Andrew Buchan as the grieving parents. But its soul was the chemistry between Colman's down-to-earth Miller and Tennant's gruff Hardy.

The second series is less a whodunit than a what-happened-next, focusing on the trial of the alleged killer.

"Because it was so naturalistic, it would be very weird to have another death in the same place, and the same team following it," Colman said.

"What was nice about the original is you go into the aftermath and the fallout. You go into the family's home and see how they continue to suffer."

The two detectives are also going through hell. Hardy is dogged by a heart condition and haunted by an unsolved case from his past. Miller has been devastated by finding out how close she was to the alleged killer.

"She's damaged, and she's had to develop a very thick skin, which she never had before," said Colman, who won a BAFTA and was nominated for an international Emmy for the show's first season.

Colman, 41, is one of Britain's most versatile performers. Her subtle comic touch livened up TV shows including "Peep Show," ''Rev" and "Twenty Twelve," and she excels at emotional anguish, as in Paddy Considine's lacerating movie "Tyrannosaur."

Colman said Miller is "just very, very lonely. Everything that she loved has just all gone sour. It's fab to play."

Even though the second season showcased some top-flight cast additions, including Marianne Jean-Baptiste and Charlotte Rampling as dueling lawyers, some viewers in Britain felt it lacked the exquisite tension of the original.

Colman puts that down to natural British contrariness: "We're a grumbling old bunch."

Despite some lacerating comments by critics, the second series still got very healthy ratings of about 9 million viewers a week. A third series has been ordered, so viewers can expect more of Colman's and Tennant's odd-couple chemistry.

"He's absolutely as delicious as you want him to be," Colman said of the former "Doctor Who" star. "He's a joy to work with.

"On the days when we had scenes apart, I felt slightly bereft. I didn't know what to do with myself without my grumpy sidekick."

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Online:

http://www.bbcamerica.com/broadchurch/

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