Blue Lights season 4 ending explained: Is this the end for Blackthorn police station?

Warning: Spoilers ahead for all episodes of Blue Lights season 4.

Sharp eyes have been saving lives once again in Blue Lights season 4, despite Blackthorn station being incredibly understaffed while fending off multiple threats.

Our favourite officers have also been dealing with heartbreak and difficult personal lives, while keeping Belfast as safe as they can from anti-immigration riots, and drug trafficking.

Dana Morgan once again reigned supreme over this season's unrest and wrongdoing, pulling the strings of her puppets before ultimately, and finally, getting what she deserves.

But what exactly went down in the finale? Let's take a look at how each character's story came to an end, in what remains the unchallenged best police drama on TV - and this had better not be the end for Blackthorn, because the future of the station did end on a rather bleak note.

Blue Lights season 4 ending explained

The Blue Lights season 4 finale picks up where episode 5 left off, and deals with the fallout from the cliff-hanger explosion involving anti-immigrant protestor Katie Close, officer Annie Conlon.

Katie, a far-right social media influencer and provocative threat throughout the entire season, was the target of a bomb. Annie had ended up as collateral damage in the explosion, and the episode begins with worried officers called to the scene of the blast, their radios announcing, "Officer down."

The bomb had been planted by the Ginley clan, who were behind all the unrest unfolding this season. From the protests at the migrant centre during episode 1, to threatening letters sent to Katie before they eventually tried to kill her, the Ginleys orchestrated everything.

Led by Dana Morgan, the Ginley crew had planned the conflict playing out to distract the police from their growing empire, allowing them to move more drugs with fewer eyes on them.

Katie and Annie both survive the blast, but while Annie is able to walk away from the scene with cuts and bruises, Katie is significantly injured and needs an intensive care admission.

Nobody is more relieved to see Annie alive than Shane, who has been pushing Colly for a proper threat assessment for his colleague, while also throwing her some fleeting looks of longing while romantic tension has built between them - they could be picking up where Grace and Stevie left off in the will they/won't they stakes.

The finale sees Colly agree to Annie's threat assessment - from the very beginning of the show, she's faced danger as someone from a Catholic community who has joined the PSNI.

It's good to see her life is finally being treated with the respect it deserves and her safety prioritised. She later sheds tears of relief when she finds the threat to her life has been downgraded, meaning she can visit home if she chooses.

With Annie's future looking brighter, she's goes straight from the aftermath of the blast to protecting Amira - Annie has spent every episode making herself constantly available to those in need to keep them safe.

Back at the station, Helen announces, "From now on, everything changes," as the police ombudsman launch an investigation into "state collusion."

When Sandra found Gerry had left behind solid proof of systemic state collusion between MI5 and Belfast's criminal underworld, she'd handed this intel over to Jen, Jonty, and Helen.

Gerry had logs detailing how MI5 consistently protected high-level criminals like James McIntyre by giving them immunity from prosecution in exchange for intelligence.

James had been recruited under this system by Colly, and others like him had been allowed to build criminal empires unchecked because of how much they were defended.

His protection was only stropped when his son Mo killed Gerry, which then crossed a line and put an end to the relationship he had with the state.

Chief Superintendent Nicola Robinson knew what was happening, and tried to defend the decision to recruit and protect people like James when challenged by the ombudsman.

But her words aren't enough, and both she and Colly are suspended from duty and it's implied that their careers are over. Nicola later visits her daughter Jen, and despite knowing her child was ultimately involved in her losing her job, Nicola doesn't hold any animosity.

Having earlier said she'd sacrificed a relationship with Jen to further her career, now is the time for the mother and daughter to rebuild and reconnect.

When the story of James McIntyre breaks on the news, Tina and Mo McIntyre's lives are immediately under threat from dissidents left outraged by his side line as a police informant.

First in line to head straight to their house in a bid to take them out is John O’Boyle. Re-introduced earlier in the season drinking through his grief in a Belfast pub, John's son Ciaran was the young lad who died in a car accident in series 3, whose death later gave Aisling PTSD.

However, when John arrives to get his revenge, the police are one step ahead and Aisling is already with Tina and Mo to protect them.

Surrounded by armed police who arrive for backup, and with gun pointed at his targets, it's Aisling who steps in talk John down.

Speaking to him gently about his son, she reminds John that Ciaran "loved you, and still loves you," as John falls to the ground in tears and lets go of his gun.

There's no getting rid of the McIntyres, as they're ultimately given the opportunity to go into witness protection and have new identities, in return for helping put an end to Dana and the Ginley operations for good.

Without the remaining McIntyres dead or behind bars, who knows what criminality they might still be able to continue. For his own protection, James McIntyre is moved to an English prison.

What happens to Dana Morgan?

Colly's final move before he bows out is to see to it that Dana is arrested. When told by Tina that their partnership is compromised and that she needs to leave, Dana is initially totally unconcerned.

But despite thinking she's untouchable, Dana's protection relies heavily on the covert network managed by Colly, and with him about to be removed from the picture along with his protections, his handlers lose control of the Belfast criminal underworld.

With no protection left, Grace has an open opportunity to swoop in and finally arrest Dana, hopefully putting an end to her operations for ever.

Afterwards, Grace and Annie pay Katie a visit in hospital to let her know who was really behind the bomb blast.

She's reluctant to believe it, but left with something to think about when Annie suggests she meet with Amira - Annie points out that she, Amira and Katie are all bound by knowing what it feels like "when something bad comes to your front door," hinting that they shouldn't allow themselves to be divided.

Six weeks later, Blackthorn really is closing. Having tried to put a stop to the closure for the whole season, Helen can't stop it going ahead and the officers are to be relocated.

The only good news comes in the form of Grace being relocated to a job she actually wants - being handed a case file Grace is told she's now a detective.

Her run of good things doesn't end there, because Stevie proposes. Hiding a ring in a cake, he asks, "New beginnings?" as a tearful Grace accepts with a simple, "Yea."

As they share an embrace and a kiss, the series comes to an end and the credits roll. Whether this is really the end for Blackthorn remains to be seen - Blue Lights is yet to be renewed for another season, but given its success, we think a return looks likely even if our favourite Peelers are separated when we see them again.

All episodes of Blue Lights are available to watch on BBC iPlayer.