Happy Valley fans have a wild theory about Tommy Lee Royce and Neil

Once there, Tommy was clearly overjoyed to see his son but, as is the usual Tommy way, he began to run the social situation, ordering Neil around to go and get them a cup of tea.

It was an unusual dynamic to watch, especially given the fact that Neil is doing Tommy a massive favour. Not to mention the fact that he's completely burnt what bridges were left between him and his sister-in-law Catherine in the process also.

But fans have been quick to rationalise Neil's involvement in the prison visits, by theorising that Neil could actually be Tommy's father. We know, it's somewhat farfetched and random, but it could be the theory that explains why Neil is involved in this whole mess.

Could Neil Ackroyd be Tommy Lee Royce's father?

Tommy's mother died at the start of season 2, prompting Tommy's fierce revenge mission against Catherine. But Tommy has never known who his father is, and Catherine also tried to figure out the identity of his father to no avail in season 2.

Neil's feet are firmly under the Cawood table this season so, of course, his relationship with Clare has also been in the eye of suspicion for many viewers. Neil had previously bumped into Clare on the street prompting the pair to form a relationship. But could it have been a premeditated plot to ingratiate himself into Clare and Catherine's life?

One Twitter user suggested: "Neil is a wrong un, there’s something not right there. I’m thinking he didn’t bump into Clare by accident all that time back."

Tommy's mother was a prostitute and so while that doesn't point to the identity of Tommy's father at all, we do know that Neil's previous affair with season 2's Vicky Fleming destroyed his family. Could it be, then, that Neil had previously cheated on his wife before too? And could he have done so with Tommy's mother?

Not much is known about Neil's past at all: we haven't met any of his family members and are yet to really know anything about what he does with his days – all we know is that he's a recovering alcoholic.

Neil's relapse in season 2 was also put down to reminders about his previous affair but one Twitter user added: "I recalled these bits from the 2nd season: Police never found the killer of TLR’s mother, did they? Did Neil relapse because of his past costly affair, or because of TLR’s mother’s murder?"

Tommy and Neil's dynamic is weird to say the least and let's not forget the mystery mobile phone that Tommy received. Viewers have said that the text language used doesn't "seem like Ryan" and others have discounted Clare – so could Neil actually be more involved in this saga than previously thought?

While we're yet to get any concrete answers, we do know that the season 3 Happy Valley ending "won't disappoint" and we can only expect that there will be multiple shocks and revelations in the coming episodes.

Clare stated that they took Ryan to go and visit his father in prison because the two had struck up a relationship previously and that Tommy managed to get word "on the outside" to Ryan that his dad had moved prisons.

But actually, what if Neil is the missing piece in the whole thing? He professes that he's scared of Catherine (and definitely seems like it) but would a man who's in fear of his partner's sister really do such a massive thing to destroy that relationship? Or could he be considering another relationship that's much closer to home?

Happy Valley season 3 continues on Sunday at 9pm on BBC One and BBC iPlayer. The first two seasons are available to watch on BBC iPlayer now.

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