It’s been two years since we last saw murdering police officer DS Elizabeth Bancroft.

The conclusion of the first series of the ITV drama saw Sarah Parish’s character revealed as a killer, desperately trying to cover her tracks as a cold case investigation into the murder of Laura Fraser caught up with her.

Having killed her old boss in a bid to keep her secret, the finale saw her attempt to murder colleague DS Katherine Stevens to stop her revealing the truth – but her life hung in the balance as the credits rolled.

With it now confirmed Bancroft had later finished the job, administering a lethal injection as Katherine fought for her life in hospital, the killer cop believed the worst was now behind her.

However, with a new murder investigation bringing estranged son Joe back into her life, the stage was then set for a blistering new chapter in the story.

Following the show’s return on New Year’s Day, here’s the nine burning questions we have been left with…

Why did Joe leave his job at the hospital?

Following the death of his girlfriend and his mum’s colleague DS Stevens, Joe’s life seems to have fallen apart, with him no longer employed at the hospital he was working at. However, his exit is somewhat shrouded in mystery.

He was particularly shifty when his mum quizzed him on his life in the intervening years since they’d last spoken, while his girlfriend Annabel revealed to the police he had been fired from his job – but why?

Why has Joe been protecting his mum’s secret if he hates her so much?

By the end of the first series, Joe knew that his mother was probably a murderer who killed both her lover Laura Frazer and his girlfriend Katherine, subsequently cutting all ties with her. He’d even told Annabel his mother was dead, having not spoken since Katherine’s funeral.

But if he hates his mother so much, why has he kept her secret all this time? Is it because he can’t cut the strong bond they originally had? Or is there another reason?

Why didn’t Michael like Joe?

Prior to Michael and Susan Connor’s deaths, there had been a family bust up over his daughter Annabel’s relationship with Joe. Michael had physically lashed out at her brother Martin when he defended Joe, with it later revealed Michael had even tried to pay Joe off to leave Annabel.

Joe had later sent Michael abusive emails, which certainly points to him having motive for killing him.

But what is the root of their hatred of one another? Was Michael just being a protective father, or does it signal there could be something more going on with Joe?

Is Joe smoking weed significant?

Bancroft is seemingly controlling the drug flow for the entire area after striking a deal with new gang leader Daanish at the end of the last series. But out for revenge, the mother of murdered gang leader Atif has been selling bad batches of drugs to sabotage Daanish for shopping his brother and working with Bancroft.

With Joe now taking illegal substances, could this suggest he is in cahoots with Atif’s mother?

Did Annabel see Bancroft watching her and Joe have sex in the pool?

Either way, the whole encounter left us very uncomfortable.

How did Annabel’s mother die and did she witness it as a child?

Historic newspaper articles revealed that Annabel’s mother died when she was a child, with her somehow connected to the case.

With a sinister side of Annabel beginning to show, could she have been responsible for her death?

Did Annabel kill Michael and Susan?

After Joe clocked that Annabel had not been in their flat on the night of the murders, she confessed to having driven to her dad and step-mum’s house, where she found their bodies. She claimed not to have called the police as she was triggered by her mother’s death.

But the episode then ended with her and Joe having sex with her step-mum’s ring hanging around her neck. This proved to be significant as Susan’s wedding finger had been broken on the night of her death, suggesting a ring was stolen by her killer.

Will Bancroft kill again?

Bancroft told her colleague she would go to any lengths to protect her son, and with him seemingly connected to this case, will she kill again?

Will Cliff finally expose Bancroft?

Cliff has had Bancroft’s number for a while now, but has been unable to prove what he knows. But with him now being pushed out of the force and with little left to lose, will he tell all?

Bancroft continues on Thursday at 9pm on ITV.