The eight-part series explores what happens to a small coastal community in Dorset, when the murder of an 11-year-old boy brings a probing police investigation and the full glare of the media.
The body of young Danny Latimer, played by Oskar McNamara, is found on an idyllic beach - but did he fall from the cliffs or was he murdered? And if so, who is responsible for his death?
"Chris, the writer, very purposely kept everyone in the dark until ... We went right up until episode seven before people knew," Andrew Buchan told This Morning's Holly and Phillip.
"I liked it. It lets it unravel chronologically. There's the ambiguity, but people aren't intentionally playing 'I am a killer' or 'I'm not a killer'."
It's so intricately woven ...
Andrew Buchan (Mark Latimer)
For Andrew's character, Danny's devastated dad Mark, there's a twist in the tale though.
In the third episode on Monday, viewers will see out-of-town Detective Inspector Alec Hardy (David Tennant) step up his questioning of the grieving father as Mark's alibi begins to fall apart.
"If we don't get the truth, we won't find who killed Danny - that starts with you!" DI Hardy shouts across the table, to the discomfort of his local partner Detective Sergeant Ellie Miller (Olivia Colman).
While Mark struggles to explain himself, claiming everything he says is being twisted, he finds himself dramatically arrested for obstructing the police investigation into his son's death.
But will he find himself facing a murder charge as well?
Fans of the show will have to wait to find out as the cast certainly aren't giving anything away.
Broadchurch - written by Chris Chibnall, who is best known for his work on Torchwood and has also been involved with Doctor Who and Law and Order: UK - seeks to rival Danish thriller The Killing.
Watch the latest instalment on UTV at 9pm on Monday, or catch up on the UTV Player.