LIAR, STV, 9pm

JOANNE Froggatt plays Laura, a trendy young teacher who goes kayaking and isn’t afraid to lift the middle finger to her cheeky pupils.

Newly single, her sister sets set her up with Andrew (Ioan Gruffudd), a widower who’s also a handsome surgeon and the owner of a sport car. Soon they’re out on a candlelit date. There has to be some catch?

When Laura wakes up the next morning she flees to her sister’s house and sobs that she can’t remember what happened after Andrew arrived at her flat. “I don’t know what he did!”

Andrew is a kind father and a doctor, whereas Laura is shown breaking up with one man only to leap at another with indecent haste, all while drinking and wearing a scarlet bra. Is she a hysterical liar crying rape, or is Andrew’s kindly image and career a clever mask for his own lies?

As she makes an allegation of rape, Andrew is bashfully confiding to friends that he really likes her, and through a series of flashbacks we begin to see what happened the night before.

THE SEARCH FOR A NEW EARTH, BBC2, 9pm

WITH the news showing horrific hurricanes and nuclear sabre-rattling, it’s natural we all feel like we’re standing on shaky ground. So in this one-off programme, Stephen Hawking looks at whether we need to forget this battered, abused, precarious planet and make a life somewhere else.

It’s been a dream of sci-fi writers for so long, but is there any reality in the idea?

Professor Hawking thinks the human race has no choice but to look elsewhere, saying we will have to establish a colony on a new planet within the next hundred years if mankind is to survive.

This search for a new home is not just down to the risks of climate change, pollution, nuclear weapons and pandemics. There might also come a time when there are simply too many of us, and not enough resources to go round. So this troubling film asks why we need to leave and, more importantly, how we would actually do it, and it all begins to sound less fanciful.