We are now midway through the second season of ITV’s gripping crime drama.

DCI Cassie Stuart and her colleague DS Sunny Khan (Nicola Walker and Sanjeev Bhaskar) continue to demonstrate a relaxed working relationship with each other which makes compelling viewing. The pair’s acting is never contrived, never competitive, but both seem to intuitively know the next stage of the case as they unravel the death of David Walker, the man whose body was dug up from a watery grave.

Parallel sub-plots emerge as the relationships between various partners are juxtaposed throughout the storyline. One theme which does stick out amongst the lives of the characters, is that one of them wants to cover up their shady past of whatever happened 10 years ago.

“That part of you, you keep from me?” says the partner of Colin Osborne (Mark Bonnar) as he tries to understand what is going on in their lives, supposedly just made complete by the adoption of a young daughter, if all goes to plan! But will it? There have been dodgy deals he doesn’t know about and a side of Colin that he doesn’t comprehend.

Meanwhile, Marion Kelsey (Rosie Cavaliero) – working as a nurse but getting far too close to one of her patients – has another complex relationship with her husband. She is often late from work, irritable, even going so far as to leave abusive telephone answerphone messages to her mum and sister as her impatience and tenseness means she loses a grip on what she is trying to hide. What about her past involvement with IRA protest marches?

The partnership trio is complete with Sara Mahmoud (Badria Timimi) who has to confess to her husband, Hassan (Adeel Akhtar) that she has been a prostitute in the past. At least she has confessed one of her secrets, unlike the others. The penalty for this is that he walks away.

Even the ex-wife of the deceased David Walker doesn’t want to contemplate any discussion with her new husband when he questions her about him.

“That was a lifetime ago” she says, but when pushed for more information, closes up and defensively asks him if there is ‘A Manual’ about how to deal with this. He responds by saying “You scare me!” She is currently a police officer to add to the complications. To be fair, this is possibly stretching the plot just too far!

DSI Cassie Stuart’s relationship with her own father is not without its secrets either. Will this be eventually connected to the plot or not? Perhaps, but the audience probably hopes not as she seems such a decent cop. Her empathy, especially with the son of the deceased, who barely knew his father, creates poignant scenes.

Contemplating that sometimes things are not always what they seem, and knowing that cozy lives and relationships can be torn apart if the trust has gone, is perhaps why this TV series has so much to keep us at the edge of our seats.

Aired at 9pm on Thursday 19 January 2017 on ITV.

Buy Season 1 on DVD on Amazon here.

Reviewed by Zoé Patrick.