Pierce Harris has become one of soap's creepiest characters, and the surprise introduction of his mother in tonight's Emmerdale tantalisingly teased some big things about his mysterious past. 

During a quiet chat with the infamous Martha, Rhona Goskirk was visibly alarmed when her future mother-in-law expressed her hopes that Pierce wouldn't make the same mistakes with her - and when she questioned what she meant, Martha nervously said that Rhona should ask Pierce herself... 

Of course defensive Pierce denied all knowledge of some big dark secret, calling Martha a deluded, manipulative fantasist and scheming parasite (and those were some of the nicer things). But the unexpected family reunion has really rattled his cage, so what do we think Mr Harris has to hide?

DID HE BEAT HIS MUM?

In a frosty, private exchange, Martha remained calm and begged Pierce to let her back in his life - but Pierce was having none of it and threatened his parent not to make him angry. As she went to lovingly stroke her son's face he grabbed her arm a little too roughly. We already know Pierce has serious anger issues, and the pain and venom in his voice when he talks about his childhood is palpable - did he ever take his anger out on his own mother? Their strained encounter ended with Martha saying: "I hope Rhona finds out the sort of man you are..."

WAS HE ABUSED?

Flipping that theory around is the possibility that Pierce himself was the victim of abuse from his mum, which would explain why he hates her so much and is such a damaged individual. Martha seemed like a sweet-natured inoffensive middle-aged lady to us, but was it all an act? Pierce insists Martha is a nasty piece of work, but she convinced Rhona into believing her account of the Harris family history in a few minutes, making her doubt months of her own finance's recollections of his childhood. And the more we saw of Martha, the more we suspected something wasn't quite right about her...  

A HISTORY OF SEXUAL VIOLENCE?

Pierce's cheating deceased ex Tess got a few mentions, but we never saw them on screen as a couple so there's a lot we don't know about what Pierce was like as a husband. Rhona has already been the victim of Pierce's sexually aggressive behaviour in controversial scenes earlier this year, and Emmerdale have already forewarned Rhona will be raped on her wedding day next week, could he have done the same to Tess? Or other women in his past? Is that 'the mistake' that Martha was referring to?

HAS HE BEEN IN PRISON?

It's safe to say this big secret is linked to Pierce's temper, so maybe he's been behind bars for his bad behaviour and that's what he's not being honest about? We wouldn't be surprised if he'd put someone in hospital with that short fuse of his. Although would he be able to practise law if that were the case? Maybe he's not actually a lawyer at all?!

DID HE KILL HIS DAD?

Talk also turned to Tim, Pierce's late father, whose death seems to be the root of his difficulties. We detected a desire to quickly change the subject when Rhona brought him up with Martha, but of course that may be because it's an upsetting topic - but what if there was more to this traumatic event than anyone's letting on? You could spend all day reading between the lines in terms of the family dynamics that have been described: a young widowed mum who neglected her kids, younger sisters that got all the attention, a put-upon eldest child -  Angry young Pierce could have had one of his tantrums as a teenager and accidentally caused his father's death. One of these theories has got to be on the money, surely?!

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