Gerry Cliff (Richard Dormer) returns to deliver a bombshell revelation, while a tide of anti-immigration violence render Grace Ellis (Siân Brooke), Tommy Foster (Nathan Braniff), and Annie Conlon (Katherine Devlin) beyond disillusioned in what's shaping up to be a characteristically pulsating fourth season of .
They've passed probation, but with the section shorthanded in the midst of a swathe of riots, nobody at Blackthorn Station is in celebratory mood. And in the wake of a vicious targeted attack, Grace, Tommy and Annie are forced to confront their methods.
Tommy and Shane's Frank Blake investigation into Dana Morgan's drug operation and links to Tina McIntyre hits the skids, just as Gerry’s murder trial gets underway, ramping up the strain on everybody, Mo McIntyre (Michael Shea) in particular.
Sandra (Andi Osho), meanwhile, realizes she's been sitting on a secret that could have major repercussions within both the police force and the upper echelons of the criminal underworld.
Read on as we explain how to watch season 4 from anywhere.
Can you watch Blue Lights season 4 for free?
. Viewers in the UK can watch season 4 on BBC One and , from Tuesday, September 29.
Traveling outside the UK or Australia? You can use a to watch your usual streaming services from anywhere.
How to watch Blue Lights season 4 from anywhere
If you're keen to watch season 4 but you're away from home and access to the show is geo-blocked, you can always use a VPN to access it (assuming you're not breaching any broadcaster T&Cs, of course). You may be surprised by how simple it is to do.
How to watch Blue Lights season 4 in the UK
Viewers in the UK can watch season 4 on and from Tuesday, September 29.
Episodes air at 9pm BST each Tuesday, however, all six parts will be available to stream as a boxset on BBC iPlayer from 6am on launch day.
All you need is an account, a TV license and a UK postcode (e.g.HA9 0WS). Sign up here.
Outside the UK? Use a VPN to gain access to all the content you'd normally stream at home.
How to watch Blue Lights season 4 in the US
is home to in the US, but at the time of publication it isn't clear when season 4 will air.
However, fans shouldn't have long to wait. Season 3 started airing on November 13 last year, six weeks after its UK premiere. Prices start from $10.99.
A VPN will help you tune in if you're a Brit spending time abroad. is our recommended provider, and you can find out why with our in-depth NordVPN review.
How to watch Blue Lights season 4 in Canada
In Canada, is available to watch on , but at the time of writing any plans for season 4 are still firmly under wraps.
It's worth noting, however, that season 3 took six weeks to cross the pond.
A Britbox subscription starts at CA$10.99/month after a 7-day FREE trial, but you'll get a better rate if you commit to a longer term.
Visiting Canada from the UK? Use to watch S4 for free.
How to watch Blue Lights season 4 in Australia
In Australia, season 4 airs for and every Sunday, starting October 4 at 9.30pm AEST.
Outside Australia? Use a VPN to gain access to all the content you'd normally stream at home.
Blue Lights season 4 – Need to Know
Who is in the Blue Lights season 4 cast?
Siân Brooke as Grace Ellis
Martin McCann as Stevie Neil
Katherine Devlin as Annie Conlon
Nathan Braniff as Tommy Foster
Joanne Crawford as Chief Inspector Helen McNally
Andi Osho as Sandra Cliff
Frank Blake as Shane Bradley
Abigail McGibbon as Tina McIntyre
Dearbháile McKinney as Aisling Byrne
Neil Keery as Sergeant Lawrence McCloskey
Andrea Irvine as Chief Superintendent Nicola Robinson
Leem Lubany as Amira Saeed
Michael Shea as Mo McIntyre
Richard Dormer as Gerry Cliff
Cathy Tyson as Dana Morgan
Hannah McClean as Jen Robinson
Jonathan Harden as Inspector ‘Jonty’ Johnston
Michael Smiley as C3 intelligence officer Paul ‘Colly’ Collins
When is the Blue Lights season 4 release date?
S4 premieres on BBC One at 9pm BST on Tuesday, September 29 in the UK.
However, the entire season will be available as a boxset on from 6am BST the same day.
How many episodes of Blue Lights season 4 are there?
Just like previous seasons, S4 comprises six episodes.
When is the Blue Lights S4 finale?
The season 4 finale will air on BBC One at 9pm BST on Tuesday, November 3 in the UK.
However, it will be available to stream on from 6am BST on Tuesday, September 29.
We test and review VPN services in the context of legal recreational uses. For example: 1. Accessing a service from another country (subject to the terms and conditions of that service). 2. Protecting your online security and strengthening your online privacy when abroad. We do not support or condone the illegal or malicious use of VPN services. Consuming pirated content that is paid-for is neither endorsed nor approved by Future Publishing.
Aatif is a freelance copywriter and journalist based in the UK. He’s written about technology, science and politics for publications including Gizmodo, The Independent, Trusted Reviews and Newsweek, but focuses on streaming at Future, an arrangement that combines two of his greatest passions: sport and penny-pinching.