After being found guilty of assaulting Alice and being fined £1,000, Rob looked to be in the clear, with his marriage to Cheryl going ahead. However, Alice managed to convince Cheryl of his deception while in the courthouse bathroom.

Noticing this, Rob faked a heart attack on the courthouse steps and was subsequently bed-bound. At the start of episode 5, it appeared he had swung Cheryl back round to believing his lies – however, she was secretly working with Alice to bring him down.

Benjy and Bill managed to hack into Rob’s laptop, while Alice worked out that Rob had been overdosing on Temazepam to give himself a slow heart rate and trick the monitor. Bill also went around the country, finding people who had also been tricked by Rob.

Meanwhile, due to the money being taken out of the scholarship account and being replaced, as well as Rob’s conviction, Cheryl was told that the scholarship would have to close.

On Rob’s laptop, Alice found that Rob has set up a second email account for Cheryl, creating a fake dialogue with himself. He had also updated her life insurance policy, so that when they got married he would receive everything upon her death, but if they didn’t marry he would still receive £1.2 million.

Rob tried to convince Cheryl that she was the manipulative, volatile and intimidating one, showing her that he had an audio recording of her shouting at her friends when the money was missing. He also claimed to have no recollection of asking for the money in the first place.

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Cheryl then began to feel unwell, with Rob having poisoned her with a glass of whisky. She vomited and managed to recover, but found he had left a suicide note in her handwriting. When she confronted him, he claimed it was his own note and that he had planned to take his own life, but changed his mind at the last minute.

At the annual Myths, Legends and Fantasy Literary Ball, held in the grounds of Cheryl’s house Arathdoon, Alice, her family and Cheryl enacted their plan to bring Rob down.

Cheryl announced the closure of the scholarship, claiming it was so she could take a step back and focus on helping Rob through a mental health crisis.

With Rob dressed as a knight, they then had Regina attack party guests and attempt to jump from the roof while wearing the same costume, making it seem as though Rob were erratic, out of control and suicidal.

Fake paramedics then made him feel as though he was delusional and seeing things, before the real police found Rob in the hedge maze, wearing only his pants and brandishing a prop axe from the party.

Rob was detained under the Mental Health Act, with Alice’s legal standing as his wife allowing her to have him sectioned. The police anticipated he would be held for at least six months.

What happened to Alice and Cheryl?

Following Rob’s detainment, Cheryl and Alice commiserated the small amount of time they had until he would be released. They agreed that during that time they would plan for his release, sorting through evidence and speaking to other witnesses to his deception.

They formed an uneasy alliance, with Alice then going home to see her family and celebrate their victory.

What happened to Rob?

BBC/Sister/Massimiliano Giorgeschi

Rob was last seen in a session with a mental health professional, during his detention. It seemed he had already started to use his old tricks again, convincing his therapist to bring him a Coke despite snacks being banned in the sessions.

It seems Alice and Cheryl may not have as long as six months after all, as Rob will use every trick he has to get out and get back to his old ways.

What happened to Sir Ralph Unwin?

BBC/Sister/Ludovic Robert

This is the biggest question left hanging from the entire series. Throughout the five-episode run it was never clear just how much Sir Ralph Unwin knew about Rob’s true nature, and whether he himself was being duped, or was a part of the ruse.

In episode 3, Unwin helped Rob convince Cheryl to send the money from the scholarship fund and save the lives of climate activists in Greenland. Then, in episode 4, Cheryl visited his house and found that bailiffs were taking his property, with Unwin describing it as a “minor financial blip”.

When Cheryl enquired about the scholarship money Unwin appeared paranoid, telling her that the Russians, the Saudis and the CIA were watching them.

When she pressed him, asking whether the situation in Greenland was real, Unwin said: “You mustn’t question it! Rob is like a son to me and he’s a good man. He has to be, because the cost to my foundation, to the entire movement if he isn’t… no, no, no, it’s unthinkable.”

The final piece of the Unwin puzzle came in one of the show’s final scenes, when news was heard on the radio saying that he had been reported missing.

So, just what did happen to him? Did he go into hiding due to the shame of his association with Rob? Or due to fear of those he believed were watching him? Or has something even more sinister becoming of the nation’s second favourite broadcaster and natural historian?

Perhaps a second season will shine a light on this but, for now, we remain in the dark as to exactly what became of Unwin.