The Cult Next Door
9pm, BBC2
In 2013, news broke of the discovery of a tiny Maoist sect holed up in an otherwise unassuming street in Brixton, south London, and of the captive women who had been subject to decades of brainwashing and abuse. Vanessa Engle’s film details the case and meets the brave and remarkably forgiving survivors (“You’re still in prison if you hold on to your hatred,” one reflects) in a profoundly disturbing and incredibly poignant documentary. Ali Catterall
Unforgotten
9pm, ITV
Episode four of Chris Lang’s cold-case police procedural and, in the wake of the big-reveal final scene last week, we seem to be getting closer to finding out whodunnit. Meantime, the lead suspects have much to contend with, what with Sara fighting to save her marriage in the wake of her confession, Colin again finding himself blackmailed and Tessa’s relationships coming under strain. Features strong performances from lead plods Nicola Walker and Sanjeev Bhaskar. Jonathan Wright
British History’s Biggest Fibs With Lucy Worsley
9pm, BBC4
Fake news is embedded in our past as well as our present. This series sees Lucy Worsley stress-testing a few cherished national narratives and finding them surprisingly flimsy. She begins with the Wars of the Roses, picking apart myths ranging from Richard III’s alleged monstrousness to Henry VII’s unifying marriage. Worsley can’t resist a gimmick – one eccentric moment sees her bombarding the camera with Yorkshire puddings – but eventually, her relish is infectious. Phil Harrison
Fortitude
9pm, Sky Atlantic
The star-studded Arctic drama that combines Scandi-noir, X-Files weirdness and an alarmingly high body count returns for a second series. Under the vigilant eye of governor Hildur (Sofie Gråbøl), the far-flung Norwegian town of Fortitude is slowly getting back to normal after the last series’ violence, despite the ominous portent of a blood-red aurora borealis. Dennis Quaid, Michelle Fairley and Ken Stott join the crammed cast just in time for a gruesome discovery. Graeme Virtue
Death in Paradise
9pm, BBC1
When the upstanding president of Commissioner Patterson’s cricket club is found dead following a victorious match and the ensuing shindig, Goodman is called in to investigate. After identifying the cause of death – a single shot to the heart, execution-style – the suspects are narrowed down to the four people who had access to the murder weapon: a pistol in the clubhouse safe. Luckily, someone left a camcorder recording the whole party. Which is obviously super-handy, evidence-wise. Ben Arnold
Spies
9pm, Channel 4
Conclusion of this silly but engaging-enough reality show conceit, in which former members of the intelligence services challenge 15 members of the public to a series of tasks, with a view to assessing their merits as potential spooks. Tonight, they are dispatched abroad – to Marrakech, for a safe facsimile of life as a clandestine operative in the Middle East. It really cannot be hoped hard enough that someone, somewhere, is at work on a Russian remake. Andrew Mueller
Divided States of America
9pm, PBS America
It’s a sad irony of Barack Obama’s time in the White House that a president who ran on uniting red and blue America leaves office with the nation more polarised than ever. That schism is largely the fault of an obstructionist Republican party but, as this fine two-parter on the last eight years shows, Obama takes a share of the blame too, not least in his failure to address the excesses of Wall Street, which birthed the Tea Party movement, and finally Trump. Gwilym Mumford
Film choice
The Purge (James DeMonaco, 2013), 11.20pm, Film4
In the future, ruined US crime rates have plummeted thanks, apparently, to the annual “purge” – a night when all crimes go unpunished. Ethan Hawke, Lena Headey and their kids are fine, locked in their max-security mansion; so long as their daughter doesn’t press that big “open-sesame” button… oh. Time for a bloody fight for survival then, with the last vestiges of civilisation splattered up the walls. Paul Howlett
Live sport
T20 Cricket: India v England Coverage of the first match in a three-game T20 series. 10.30am, Sky Sports 2
X Games Aspen 2017 Day one coverage of the extreme sports event, featuring the Snowmobile SnoCross final. 6.30pm, BT Sport & ESPN
League Cup Football: Hull City v Manchester United United head to the KCOM Stadium, holding a 2-0 lead from the semi-final first leg. 7.30pm, Sky Sports 1
