Psychological thriller Liar has potential to keep you guessing

In the opening episode at least, each plot development seemed to follow on neatly from the last.

We met newly-single secondary school teacher Laura and single dad Andrew. They had a romantic date at a fancy restaurant, which ended with the two of them unexpectedly back at Laura's flat drinking wine and having a laugh. But each of them has wildly different interpretations of what happened next: Andrew insisted they had consensual sex, while a distraught Laura reported him to the police for rape.

Considering the way the story was set up, each development seemed inevitable. Of course Andrew went for the classic line, "I think there's been a mistake" as he was arrested at work. Of course he turned up at the school and barged into Ms Nielson's classroom, terrifying her into absolute panic.

Andrew happens to be the father of a boy in Laura's class, and while this makes the situation even more plausible (according to Rape Crisis 90 per cent of rape victims know their rapist), the Williams brothers have added a web of extra connections add to the dramatic potential.

All of which unfortunately take away from the central allegation: of course Andrew happens to be the colleague of Laura's sister at the hospital; of course Laura's sister is cheating on her husband and having an affair with Laura's recent ex; of course Laura's ex-boyfriend works for the local police force.

But despite all this, Liar will get people talking. The public will become the judge and the jury, and fans will have theories. They will seize on little clues, like that line about, "what happened last time" – has Laura accused someone of rape before? But just when one side of the story seems more plausible than the other, the Williams brothers tip the balance back again.

While the first episode contains a lot of obvious setting-up, there are also five whole episodes left to play with. We've been promised twists and turns, and as creators of The Missing the writers have form for being particularly good at that. We have also been promised a payoff: halfway through the series we will find out who's telling the truth – and who's the Liar.

But that comes with its own complications, doesn't it? The screenwriters have asked the public to avoid a "knee-jerk" reaction to the storyline, and have defended themselves from questions about the impact of casting doubt on Laura's rape by telling audiences to wait and see.

But to make Laura the liar could have a devastating impact, and they must know that.

This is not, of course, untrodden territory – even if it remains deeply uncomfortable to watch. Liar executive producer and director James Strong was nominated for a Bafta for his work on Broadchurch, a show that went on to tackle a difficult rape storyline. And in National Treasure, writer Jack Thorne also made the audience wait to find out until the end whether Robbie Coltrane's character was guilty of rape.

How does it compare? It's decent – but a little clunky. Hopefully Liar has more tricks up its sleeve for the rest of the series.

Still, Liar's big strength is really in the acting: Joanne Froggatt's Laura is heart-breaking, and frustrating, and entirely believable. Ioan Gruffudd's Andrew is convincingly charming, and seems genuinely to believe in his own innocence. With weaker actors this show might die, but with these two? They'll keep you guessing until the big reveal.