It's the hot-topic thriller that's got everyone talking, but how will ITV's Liar wrap things up in tonight's final episode?

Last week's penultimate outing saw Laura (played Joanne Froggatt) and DI Vanessa Harmonfinally catch serial rapist Andrew (played by Ioan Gruffudd) red-handed, only for the villain to wriggle out of their grasp.

Joanne has promised that the series closer will provide a "satisfying conclusion" – but has also hinted at some questions going unanswered, leading to the "possibility of doing a second season".

So, thinking along those lines, we've come up with a few theories as to how things might turn out - some happy, some tragic, and a few that land somewhere in between.

1. Andrew is brought to justice

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The most simple solution: Andrew is finally caught out, his long list of crimes exposed, with DI Harmon and her partner DS Rory Maxwell helping Laura to put the monster behind bars.

How? Well, surely the stash of evidence hidden in his mother's shed will come back to haunt him?

Amongst Andrew's kit is a batch of small vials containing GHB, as well as a video camera. We even see him watching back some of the footage he's captured, presumably out of a twisted need to revisit his crimes.

Could someone discover this footage and use it against him? Surely the security tracker on Andrew's car – which Harmon previously used to follow him to the beach – will show he stopped off at Sylvia's?

2. The rape ring theory

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"We're going to find proof that you raped me!"

"No, you won't, Detective... no, you won't."

Why is Andrew so convinced he'll get away with raping Harmon? Is he now just that confident in his ability to commit these crimes without leaving a single forensic trace... or is there another explanation?

Some fans are still banking on the Liar finale delivering one last big twist – that Andrew isn't working alone, that someone else is actually raping these women, and he acts only as a facilitator.

We saw him drug Laura, and break into Harmon's house – but in both cases, we never actually saw what happened next. Simply a matter of taste, or a way of concealing this turn in the plot?

3. Laura kills Andrew

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Unable to bring Andrew to justice by traditional means... could she go that far?

Laura's already made it clear that she's determined to see Andrew pay for what he's done, even if it costs her dearly. "I don't care about me!" she protested this week. "All I care about is him answering for what he's done!"

She's already drugged him, kidnapped him... is murdering Andrew the only way to stop him? It'd be a helluva tragic twist – Andrew's reign of terror over, but Laura thrown in jail by a reluctant DI Harmon.

Or maybe Harmon helps her to cover up the crime? Could series two be about the cover-up, the lie of what happened that night?

4. Jennifer kills Andrew

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Jennifer (played by Jill Halfpenny), in case you didn't know, is DI Harmon's girlfriend and a soldier serving in Iraq, who made a brief appearance in episode 4 of Liar via video call.

She was absent the following week, which suggests Jennifer will have a larger role to play in tonight's finale – you don't hire an an actress of Jill Halfpenny's stature for a single-scene cameo.

Fans have even been speculating that she'll hunt Andrew down after discovering what happened to Harmon. It might not be a coincidence that Jennifer's a soldier (read: physically capable of taking Andrew down, and perhaps inflicting a lot of pain).

5. Andrew's life will end up in tatters

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Now here's a thought: perhaps Liar won't end with Andrew behind bars or six feet under, but with the villain facing punishment of a different kind.

Remember back in episode 3, when Andrew lied to the overbearing father of schoolgirl Makeda, insisting that his daughter was merely dehydrated, when in fact she'd just aborted her child with Andrew's son Luke?

He told the lie to make himself look good – at the time, Andrew was desperate to convince Laura that he was a "nice guy" – but could it come back to haunt him? Since he's got away with rape, could he end up facing a charge of medical malpractice or similar?

It'd be a bittersweet ending – no jail time for Andrew, but he loses his job and his reputation is destroyed, with the police keeping a beady eye on him in the future. Hardly the punishment he deserves, but it's a sad fact that only a very small percentage of reported rapes (less than 6%) end in a conviction for the perpetrator.

6. Tom goes rogue

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What next for Tom? It's possible we'll see Liam take the dodgy copper to task for sleeping with his wife Katy – but will Tom also play into Andrew's downfall in some way?

He's a master at making poor life choices, both personal – the affair with Katy – and professional – supplying Laura with GHB, and instigating a groundless search of Andrew's home, which led to his suspension from the police service.

Rejected by both Laura and Katy, and with no job, it appears Tom has nothing left to lose – might he go after Andrew on his own? If he does, it might allow Andrew to play the harassment card again, and come away looking like the victim. If he lives to tell the tale, that is...

From: Digital Spy