Written by Barry Hines and directed and produced by Mick Jackson, it is a dramatic account of nuclear war and its effects in Britain, specifically on the city of Sheffield in Northern England.

It has been called "a film which comes closest to representing the full horror of nuclear war and its aftermath, as well as the catastrophic impact that the event would have on human culture.

The situation rapidly escalates when the USS Los Angeles sinks and American troops are deployed to unoccupied western Iran to defend its oil supplies.

News of the breakout of fighting spurs British citizens into panic buying and looting, resulting in the enabling of emergency government powers across the UK for civil defence purposes.

Officials of Sheffield City Council and many others across the nation take shelter in makeshift basement bunkers to command the area should central government be destroyed, with many being forced to leave their families behind.

As Britain prepares for the possibility of nuclear war, over the course of two days society gradually destabilizes as panic buying, looting, and violent suppression of anti-war protests takes place across the country.

Early in the morning, the Soviets launch a nuclear strike, first disabling communications across Britain and northwestern Europe before attacking NATO military targets, then economic and industrial centres.

Jimmy attempts to find Ruth and is never seen again, his brother Michael is killed in the initial firestorm, his mother is horribly burned and later dies, while his father suffers from the subsequent radiation poisoning.

Making her way to the countryside near Buxton, where local authorities unsuccessfully attempt to convince the residents to house refugees, she is reunited with Jimmy's friend, Bob, for a time.

Children born after the war speak a reduced and broken form of English due to the absence of organised schooling, the long-term psychological effects of fetal radiation exposure, and the elective mutism of adult survivors.

Our intention in making Threads was to step aside from the politics and – I hope convincingly – show the actual effects on either side should our best endeavours to prevent nuclear war fail.

[citation needed] Jackson subsequently travelled around the UK and the US, consulting leading scientists, psychologists, doctors, defence specialists and strategic experts to create the most realistic depiction of nuclear war possible for his next film.

[12] As part of their research, the two spent a week at the Home Office training centre for "official survivors" in Easingwold which, according to Hines, showed just "how disorganised [post-war reconstruction] would be".

[14] The scenes taking place six weeks after the attack were shot at Curbar Edge in the Peak District National Park; because weather conditions were considered too fine to pass off as a nuclear winter, stage snow had to be spread around the rocks and heather, and cameramen installed light filters on their equipment to block out the sunlight.

[15] For the horror of Threads to work, Jackson made an effort to leave some things unseen: "to let images and emotion happen in people's minds, or rather in the extensions of their imaginations".

In Canada, Threads was broadcast on Citytv in Toronto, CKVU in Vancouver[26] and CKND in Winnipeg,[27] in New Zealand on TVNZ in September 1984,[28] and in Australia it was shown on the Nine Network on 19 June 1985.

In all these cases, the original music over the opening narration was removed, again due to licensing problems; this was an extract from the Alpine Symphony by Richard Strauss, performed by the Dresden State Opera Orchestra, conducted by Rudolf Kempe (HMV ASD 3173).

On 9 April 2018, Simply Media released a Special Edition DVD in the UK, featuring a different 2K scan, restored and remastered from the original BBC 16mm CRI prints, which Severin did not have access to.

"[36] Rick Groen of The Globe and Mail wrote that "[t]he British crew here, headed by writer Barry Hines and producer/director Mick Jackson, accomplish what would seem to be an impossible task: depicting the carnage without distancing the viewer, without once letting him retreat behind the safe wall of fictitious play.

Its power may be the effect of its oscillation between form and content being so heavily weighted toward the pole of content—in this case, that threat of nuclear destruction which cannot help but feel 'real'--so that we are unable to relax into Threads as 'just' a movie.

The critical consensus reads: "An urgent warning against nuclear conflict, Threads is a chilling hypothetical that achieves visceral horror with its matter-of-fact presentation of an apocalypse".

[35] Peter Bradshaw of The Guardian called it a "masterpiece", writing: "It wasn't until I saw Threads that I found that something on screen could make me break out in a cold, shivering sweat and keep me in that condition for 20 minutes, followed by weeks of depression and anxiety".

[41] Sam Toy of Empire gave the film a perfect score, writing that "this British work of (technically) science fiction teaches an unforgettable lesson in true horror" and went on to praise its ability "to create an almost impossible illusion on clearly paltry funds".

He praised the pacing and Hines' "impeccable" screenplay and described its portrayal of the "immediate effects" of the bombing as "jaw-dropping [...] watching the survivors in the days and weeks to come is heart-breaking".