Blue Lights season 3 recap: Everything to remember ahead of season 4

Happy Blue Lights season 4 day to all who are celebrating and tuning in to the epic police drama.

The peelers are back, with six new episodes airing on BBC One and BBC iPlayer from September 29.

Sharp eyes are saving lives once again as our PSNI favourites are thrown into their "toughest shift yet" and everything kicks off as protests outside a migrant centre descend into riots.

Gerry Cliff's murder trial is also underway during season 4, and uncovered evidence he left behind will leave everyone reeling.

But before you settle down for the new episodes, are you the sort of person who starts a new series but needs to pause because you can't quite remember what happened in the previous one?

Us too, which is why we've put together a handy season 3 recap with everything you need to know before tuning into season 4.

Blue Lights season 3 recap

As season 3 opens, viewers get to see that after a lot of building tension and touch-and-go, Stevie and Grace are finally a couple. They’re even living together and looking for a home of their own.

That’s pretty much where the good news ends though, and it’s straight into the gritty realism this show is so brilliant at.

Out working together, Grace and Stevie end up involved in a drug bust involving a dealer called Sandy, whose accomplice, a young girl, escapes the scene.

Afterwards, Grace is looking over some captured images of the pair and realises she recognises the running girl as Lindsay, a child she met in the care system when she worked as a social worker.

Shane and Tommy later respond to a call about a collapsed man at a private club in the city, The Deanery. Run by this season's super villain, Dana Morgan, this club becomes the hub from which the biggest storylines from the show play out and links to the drug dealer Grace and Stevie just busted.

The collapsed man bought cocaine from Sandy and Lindsay through an app. While he’s unconscious from an overdose in hospital, Shane wants to wrench his eye open to use his retina to unlock his phone and find out where the drugs are coming from.

All he can access is some chats, and nothing to trace the people at the top of the drug chain. While Tommy protests that what Shane is doing is unethical, Shane quickly snaps photos of the chats but is interrupted by a doctor who makes it clear the officers need to leave.

These actions nearly see him dismissed later in the series for misconduct of evidence, and the collapsed man is actually crooked accountant George McLelland, who cooks Dana's books for her criminal dealings.

Elsewhere, Tommy and Aisling are still a couple and living with Annie - she is having a difficult life outside of work. Her mum is dying and obviously she wants to visit her, but this is incredibly dangerous because of both her Catholic background, and choice to become a police officer - paying her a visit would mean risking her life.

In what should be good news for Stevie but he doesn’t exactly seem ecstatic, Sandra suggests that he’s temporarily promoted to ‘skipper,’ or sergeant. He's right to be wary, as his first shift is a chaotic disaster.

Viewers are introduced to Paul ‘Colly’ Collins, a former colleague of Helen’s. His role at the station is to carry out a top secret, high-level intelligence operation involving Dana and the Ginley network.

Colly steps in when Sandy is arrested, offering to help get him out of a life of crime in exchange for being a police informant.

Sandy agrees just before he’s asked to meet the enforcer Fogarty at Matchett's Mill. He lets Lindsay know where he's going, who is now back in touch with Grace.

Lindsay gives Grace Sandy’s whereabouts, but as she arrives there with Stevie, Fogerty pushes Sandy to his death from the roof and his body lands in front of their car.

Without Sandy, Lindsay is left without protection and Fogerty makes it clear she'll be forcibly sent to Dublin to "work" in one of his clubs. Grace discovers Lindsay is one in a long line of girls who've been trafficked into sex work under similar circumstances and the care system are too under-resourced to stop it.

Later, when Aisling and Annie are called to a rush to a road smash, Aisling is left devastated and in shock when Ciaran, the young driver dies in her arms.

Evidence found at the scene points to the lad being a "clean skin," or someone with no criminal record acting as an asset for a dissident republican faction.

Colly finds Ciaran has links with Dana Morgan - she has been enlisting and dissident republicans to expand her drug network - she's left white-collar drug running behind to actively sanction extreme violence.

Dana targets Chief Superintendent Robinson, whose husband is a frequent visitor to her club, although his wife is unaware of what goes on there.

Using George's digital footprint to find out the Chief Superintendent's home address, Dana passes this to local dissident republicans who plant a bomb under her car. The bomb is found, but Nicola and her family need to leave their home quickly and move to a safe place.

By episode 3, Annie has made the dangerous move to visit her mum, and is constantly checking for threats and bombs under her own car, rattled by what happened to Nicola.

Sadly, her mum passes away, leaving the young officer understandably in a state of grief. She's later called away from the wake after a credible threat to her life is discovered.

The team at Blackthorn put together a makeshift funeral service inside the safety of the station, remotely live streaming the real funeral for the heartbroken officer.

Aisling seems to be suffering from something like PTSD after the car crash death, often praying and starting to break the rules at work - when she's rattled by a domestic call to a fellow officer's house, she later returns to the house off the clock without anyone knowing, putting herself in danger.

She then puts a lot of people in very serious danger when she breaks protocol to visit the dissident republican parents of the boy who died in the car crash.

The reckless, unauthorised decision looks like it'll get her killed, but eventually takes a human turn when the parents unexpectedly hand her a list of names associated with the group, to be used in police investigations.

Aisling is suspended from duty and made to attend a residential treatment facility to recover, before she can return to active duty.

Meanwhile, Colly meets with crime matriarch Tina McIntyre - she wants him to secure her son Mo's release from prison, who is on remand for Gerry Cliff's murder.

After the McIntyre family were pushed out of the drug trade by Dana Morgan and Donal Fogerty, Tina offers to trade secrets about the Ginley network with Colly in exchange for her son's freedom, in order to reclaim her territory and take down her rivals.

Elsewhere, Grace is still struggling to protect Lindsay, and eventually gets through to her by sharing her own painful history in the care system - this was something audiences weren't aware of until now.

Lindsay eventually confesses everything she knows about trafficking and forced sex work in Dublin, and also handed over some names of those involved to Grace - the names are piling up.

Lindsay's intel allows Grace to track down and arrest George McLelland, the bent accountant laundering millions for Dana's drug enterprise.

Dana, realising he knows too much, arranges for her accountant to be silenced. While Grace is driving the transport vehicle with him on board, they're ambushed by hitmen and Grace is backed into a corner.

DI Louise Kerrigan steps in behind the scenes, expertly guiding Grace through the crisis and saving everyone involved.

Shane, having been stabbed in the leg during a routine call to a restaurant, by a customer experiencing cocaine-induced psychosis, reflectively recovers in hospital. The evidence misconduct case against him is dropped and he can return to duty when fully healed.

As the series begins to wrap, Tina's son get the early release promised by Colly. Now considered a snitch, Fogerty and Dana want Tina gone.

Fogerty arranges to meet Tina at a quiet quarry. But just when it looks like things are about to go south for her, Lee Thompson (from series two) takes the role of sniper and unseen from the quarry edge takes Fogarty down.

In the closing moments, viewers see that Helen has been promoted and will head up the classified, long-term intelligence operation to infiltrate Dana Morgan's club and crime network.

That opens the door to season 4, which should pick up where season 3 left off.

All seasons of Blue Lights are available to view on BBC iPlayer.