The Fall (BBC2, 9pm)

WITH a title almost predicting a comeuppance, it seemed just a matter of time before the critics tired of this psychological thriller which has been shunted into a Friday finish, abandoning its Thursday slot.

When the series burst onto our screens in 2013, viewers were initially gripped by the cat-and-mouse story of serial killer Paul Spector and his nemesis, Detective Superintendent Stella Gibson (Gillian Anderson).

Spector wasn't really like any on-screen murderer we've seen before. He wasn't a loner, a seedy individual existing in the shadows. Instead, he was depicted as a happily-married man with two children, and was played by former male model Jamie Dornan, an attractive individual and no mistake who has since become a global star thanks to his role in the movie 50 Shades of Grey.

Many viewers and critics felt that the story could have ended after the first run, but writer Allan Cubitt extended the story for a second run, which aired in 2014. Spector was eventually apprehended by Gibson, but at the end of the series, was in a critical condition, having been shot several times.

That paved the way for a third series, and for much of it, Spector has been in hospital, recovering from the aforementioned wounds. He's now represented by a slick lawyer who doesn't seem to care whether his client is guilty or not – it's all about showing how clever he is by getting Spector off the hook; to literally enable him to get away with murder.

"The Gibson/Spector relationship is strange," admits the actress. "They have an equal obsession for each other. It's very much a cat-and-mouse dynamic. They confound each other, frustrate each other, and infuriate each other. One of them is always slightly on top and I think that is the nature of their relationship at any given time. They've both caught each other out, surprised each other with their tactics and that psychological interaction is titillating for them at the same time.

"Stella has been violated by him a couple of times and she's not used to people having that power over her. She's used to being the smartest one in the room and she can hold herself in any situation. So to be tripped up, caught out and exposed is a huge knock for her."

However, the get-out-jail antics involving a laughable level of security at a "secure" mental health facility and the ineptitude of another bamboozled crop of detectives is hardly the ideal scenario for Gibson and Spector to reach a conclusion.

Secrets of Great British Castles (C5, 8pm)

HISTORIAN Dan Jones begins a new run of the series in Edinburgh. These days, the city's stunning castle is a well-known landmark, but it has had a traumatic past and is widely thought to be Britain's most besieged stronghold. Its hilltop location made it the ideal place for an Iron Age base, and the spot has housed a military facility ever since; it is also Scotland's most popular paid tourist destination and an event that took place there is said to have inspired the Red Wedding in Game of Thrones. Jones also discovers that the castle was the target of the world's first aerial bombing before finding out about the gruesome facts about some of the bloody deeds that occurred while James II was a resident.

Britain's Greatest Bridges (C5, 9pm)

ENGINEER Rob Bell tells the story behind the design and construction of Isambard Kingdom Brunel's famous bridge over the picturesque Avon gorge at Bristol, and discovers that some people question whether it was entirely the product of his own devising. The bridge remained unfinished in Brunel's lifetime, but when he died in 1859, his friends decided that the bridge should be completed as a memorial, using the chains from another of his suspension bridges that was being demolished.

Viv Hardwick