TV tonight: the weird, wild story of kidnapped racehorse Shergar

Shergar: The Racehorse and the IRA

8pm, Channel 4
“Somebody comes up with the idea that they’re going to kidnap a racehorse.” In 1983, Shergar was the most valuable horse in the world, worth about £10m. But with the IRA in need of funds, three men in balaclavas with machine guns stole him and demanded a ransom. The extraordinary story is told by racing insiders including commentator Derek Thompson and journalist Lissa Oliver. Hollie Richardson

Britain’s Got Talent: Live Final

7pm, ITV1
It’s time to choose a winner! The Golden Buzzer finalists include dance group LMA, drone artists Celestial and fire juggler Liqei Yang, along with public vote finalists Anastasiia and her dancing collie dog Salsa, the Hawkstone Farmers’ Choir and magician Fabian Fox. HR

Casualty

8.25pm, BBC One
The miniseries spin-off from the geriatric hospital drama continues. This week, Flynn discovers that Col Bard is something worse than a domineering army officer when a callout leads to two injured soldiers. Meanwhile, in this time of high tension and ever more demanding work, Dylan confronts his alcoholism. Jack Seale

Monsieur Spade

9pm, U&Drama
It’s set in the sun-soaked south of France but the reinvention of the classic private eye starring Clive Owen has a pervasive air of darkness. This time, Spade gets his hands on the man who has broken into his house and, via a long, nasty interrogation, gets some information. It’s not great news: everyone seems to want him dead. Phil Harrison

Two Weeks in August

9.15pm, BBC One

Antonia Thomas in Two Weeks in August. Photograph: PHOTOGRAPHER:/CREDIT LINE:Various Artists Limited/BBC/Colin Hutton

The morning after the night before, Zoe (Jessica Raine) is choosing to forget she saw her husband snogging her mate. But that doesn’t stop the gossip from spreading to the rest of the group. It’s awkward, then, when they all board a boat for a day trip. Expect more trippy turns – and a biting incident – in this holiday-gone-wrong drama. HR

Nobody’s Fool

9.30pm, ITV1
After Monday’s shock withdrawal, this new bluff-heavy quizshow ups the ante as the remaining contestants vote to eliminate once again. With Ella harshly accused of manipulating others, the atmosphere is tense – then a maths challenge compels Billy to put “morals and scruples aside and just focus on winning the money”. Nicole Vassell

Film choice

Ghost Trail, 9.05pm, BBC Four

Adam Bessa in Ghost Trail. Photograph: Album/Alamy

In 2016, a group of exiled Syrians in Europe are tracking down war criminals from the Assad regime. Hamid (Adam Bessa) thinks he has found one in Strasbourg, posing as a university chemistry student. But as he surveils him, Hamid’s increasing certainty that this was the state official who tortured him in prison bumps up against a lack of definitive proof. In Jonathan Millet’s slow-burning, fact-based French thriller, the hunt for justice is warped by obsession and PTSD, with Bessa taut and locked-down as the literature lecturer turned amateur secret agent. Simon Wardell

Live sport

Cycling: Giro d’Italia, 9.15am, TNT Sports 3 Stage 20 from Gemona del Friuli to Piancavallo. Coverage of the women’s race starts at 4pm.

Tennis: French Open, 9.30am, TNT Sports 4 Day seven at Roland Garros.

Challenge Cup Rugby League: Wigan v St Helens, 11.15am, BBC Two The women’s final at Wembley. Followed by Wigan v Hull KR in the men’s final at 2pm on BBC One.

Prem Rugby Union: Saracens v Harlequins, 12.30pm, TNT Sports 1 From StoneX Stadium.

Women’s T20 Cricket: England v India, 2pm, Channel 5 From Bristol. The final game is on Tue, 6pm, Sky Sports Main Event.

Champions League Football: Paris Saint-Germain v Arsenal, 3pm, TNT Sports 1 Martin Ødegaard captains the English team in the final in Budapest.