Grace drops almighty twist with game-changing revelations for key character

The first sense the episode would be as monumental as it was came around the midway point, when all signs pointed to Brad Morrison's Nick Nicholl, a long-standing member of Roy's team, being corrupt.

With a missing gun having been handed in to an undisclosed police officer, Nick acting shifty regarding his movements and his having handed in a corrupted file, all signs pointed to his having been a snake in the grass, working for a local gang, the Benchdale OCG, the entire time.

However, when pressed Nick revealed to Roy that his strange behaviour of late had actually been because his wife had kicked him out of the house and planned to move away with his son.

Roy was unsure whether to believe him, and Nick was briefly suspended pending an investigation. However, it soon became clear something else was going on and Nick had been framed.

In actuality, it was ACC Cassian Pewe who had been stifling their investigation, and working for Benchdale OCG, helping to cover up their misdeeds.

Cassian was first introduced in the show's second ever episode, and was originally played by James D'Arcy, with Sam Hoare later taking over.

Cassian and Roy had a fraught history, as the former had tried to pin Sandy's disappearance on him, claiming he had murdered her. However, they had in more recent times come to work effectively together.

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Throughout the episode, Cassian committed multiple murders both to shield his own actions and those of the gang. He also erased data to cover his tracks, but the team managed to restore some files, proving his guilt.

After a showdown with Roy, Cassian was arrested. Before they questioned him, Glenn revealed to Roy that Cassian had previously deleted a CCTV file showing him seeing Sandy on the street – he had known she was alive well before Roy did.

As Roy questioned him, Cassian revealed the truth. He had been having an affair with Sandy before her disappearance. She had come to him as Roy was never present or there for her.

Sandy had got deep into gambling debt, and owed £200,000 to the Benchdale OCG. They planned to kill her and her unborn child, with Cassian revealing he knew about Sandy's pregnancy and about Bruno long before Roy did.

Sandy believed she couldn't rely on Roy, so Cassian got her a new identity and allowed her to disappear, so the gang couldn't find her. She promised she would let Cassian know when she was safe, but she never did. Cassian said this is why he pursued Roy for her murder – he believed he genuinely could have killed her, if she had found out the truth and been able to find her.

Once Sandy died at the end of season 4, and the gang found out about this, her debt to the gang had to be paid. It fell to Cassian to pick it up, so he started to work for them. Initially it was only meant to be a few favours, to stop them from killing him.

However, when one of his victims, Hannah, threatened to expose his corruption, he felt he had to kill her.

It was a huge reveal, which will no doubt have left Roy and the team reeling. Who will take over as ACC now that Cassian is seemingly going to prison? Will they face further consequences for his actions? And is that the final word we'll get on Sandy and what happened to her surrounding her disappearance?

With a sixth season having already been commissioned, we may well find out the answers to these, and more questions.

Grace season 5 will continue on Sunday 27th April 2025.

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