Protection offered the best of ITV thrillers - a bent copper storyline worthy of Line of Duty, and a leading lady straight out of Happy Valley - and the ending definitely kept us on our toes. In the word of Paul Brandish just days before he died: "Don't trust anyone."

The six-parter followed DI Liz Nyles - later Acting DCI when Arun Kapoor was 'retired' - who worked in the secretive and high-stakes world of Witness Protection. When one of her protected persons was shot dead along with his wife, their daughter witnessed it all.

Viewers will know that Liz's colleague - and secret lover - DC Paul Brandice was also at the safe house when the killings happened. But he had no reason to be there at all.

So was he compromised? Who leaked the location of the safe house? And how was Brandice's army friend John Gibson involved in it all? Here's Protection's ending explained, and news on a possible series 2.

***Warning: spoilers from Protection series 1 ending below***

Protection ending explained: Who killed Jimmy McLellan?

DI Liz Nyles was horrified to discover that Jimmy McLellan and his wife were shot dead while under her protection. But why, and by who?

At first, Ed Crowther was the prime suspect as his accountant McLellan was due to testify against him. Or so we thought.

However, Liz slowly uncovered the truth. Eddie Crowther did not organise the hit on Jimmy McLennan. In fact, the real villain was British Intelligence Officer John Gibson - aka Nigel Frankton - who had been "pulling the strings all along". It was a cover up.

Explaining why he killed McLellan and later DC Paul Brandice to Liz, he said: "When McLennan turned on Crowther, I knew our arrangement was over. Trouble was, McLellan knew a lot more than he let on to the police, and I couldn't risk it."

He added: "The UK has foreign policy goals that cannot openly be pursued. I further those goals. I do things the government is too weak to do."

We learnt that John Gibson handed over weapons illegally to Kurdish fighters, with Crowther as an accomplice. Crowther got money, while Gibson got the distribution network. With Crowther as his "frontman" Gibson had "plausible deniability".

As an Intelligence Officer, Gibson - real name Nigel Frankton - was smuggling weapons from the UK to arm separatists, and using Crowther as cover.

He believed he was furthering UK's foreign policy goals, but what he did was completely beyond his authority. He worked alongside Elliot Hughes.

Thanks to Liz, their behaviour was brought to light at the end of Protection, and would be "dealt with quietly in house".

Who was John Gibson, aka Nigel Frankton?

John Gibson (Jonathan Cake) was a trusted army friend of DC Paul Brandice from the army. However, his real name was Nigel Frankton. So why the fake name?

Paul's wife Gemma exposed the truth when she saw a picture of 'John'. She told DI Liz Nyles that John was in fact Nigel Frankton, and that he worked as a senior officer in British Intelligence.

In fact, John - using his alias - did work for the security services. And he was the missing link to Ed Crowther AND DC Paul Brandice.

DI Liz Nyles worked out that John/Nigel and Crowther had worked together, and Jimmy McLellan knew about their relationship. When Jimmy threatened to expose their relationship, John/Nigel "shut Jimmy up" and framed Crowther for it. There was a vital piece of evidence at the safe house, which John Gibson - aka Nigel Frankton - was trying to find.

That's why the gun that filmed Jock Ferguson - Crowther's henchman and one of the shooters in the McLennan house - turned up in Crowther's house. Gibson planted the gun. John/Nigel also met Liz in a car linked to Crowther to make her think they were connected.

Finally, he planted Paul Brandice's phone in one of Crowther's properties so the police would find it and make the obvious connection.

Protection recap: Who was Edward 'Eddie' Crother?

Edwards 'Eddie' Crowther was the head of a criminal gang who operated a "heroin pipeline" bringing the drug into the UK.

Jimmy McLennan was a white-collar career criminal who worked as Eddie Crowther's accountant. When he offered to testify against him in court, Jimmy was put into witness protection alongside his wife and child Amy. Of course, Jimmy and his wife were murdered in the so-called safe house.

After that, all other witness were then too scared to testify against him. However, although Crowther was a morally ambiguous piece of work, he was NOT behind the murder of Jimmy McLellan and his wife.

In fact, in the final episode of Protection on ITV1, Crowther agreed to work with Liz against John Gibson. However, he too was silenced. Moments before he'd planned to speak to DI Liz Nyles on a phone from prison, he was jumped and strangled to death. The culprits made it look like he'd taken his own life by hanging himself from his bed sheets.

His killer? Of course, it was John Gibson aka Nigel Frankton.

What was the link between John Gibson and Eddie Crowther?

Eddie Crowther helped fund the Kurdish Independent Movement by providing weapons. They in turn sold drugs to Eddie Crowther.

However, after a time, the weapons started getting better, in exchange for political interference in Iraq politics.

John Gibson handed over weapons illegally to Kurdish fighters, with Crowther as an accomplice. Crowther got money, while Gibson got the distribution network. With Crowther as his "frontman" Gibson had "plausible deniability".

Protection ending explained: Was DC Paul Brandice corrupt?

In Protection, a suspenseful conspiracy thriller on ITV, DI Liz Nyles (Siobhan Finneran) was desperate to find out if her lover DC Paul Brandice was corrupt. The trouble was, she broke all the rules trying to cover up the affair.

So did Edward 'Eddie' Crother have Paul Brandice in his pocket? And how had Paul been employed by the Protected Person's Unit without being properly vetted?

We know that Paul pushed to join witness protection, and lied about his reasons. When the McLellan family were targeted by gunmen, it looked like Paul was the leak. How else would the hitmen have known where the protected family was?

Of course, Paul Brandish was eventually silenced when he was murdered in his hospital bed while recovering from a gunshot wound. We later discovered that he had a vital bit of evidence - described as the McLellan's "insurance" - against Crowther and John Gibson.

Ultimately, Brandice was corrupted, if not corrupt. He thought he was working within the law. Senior Intelligence Officer, and his old army mate, Nigel Frankton - working under his new name John Gibson - had put him in a compromising position.

Was DCI Amanda Kelman the leak?

After DC Paul Brandice was shot in the safe house, he remained in hospital with life threatening injuries. So when the location of Amy's police interview was leaked, there were only a handful of people who could have been the mole.

Also, we know that Amanda Kelman lied about DC Paul Brandice's condition in hospital to keep Liz away.

But yes, Amanda Kelman was the mole who leaked Amy's whereabouts and put her life in danger. However, like Paul Brandice, she believed she was just doing her job. A senior intelligence officer had requested the information, and she was following the chain of command.

When confronted, Amanda told Liz: "Scrubbing the hospital CCTV, framing DS Kholi, the death of DS Brandice - Frankton and Hughes did those things, not me."

During the tense Protection ending, she added: "Frankton needed a serving police officer inside Protected Persons to infiltrate the McLellan safe house. So he gave his ex-army mate a tap on the shoulder. Brandice would have assumed he was participating in a officially sanctioned intelligence operation, just as I did."

Protection ending explained: What happened to DI Liz Nyles?

At first, DI Liz Nyles was charged with perverting the course of justice. After all, she had hidden Paul's burner phone from the police to protect herself, and to be able to continue protecting Amy.

Her motives were generally good. She certainly wasn't a villain. Liz was subsequently bailed and suspended from duty.

However, when she continued to investigate the case, Wheatley arrested her for breaking her bail conditions.

Of course, having heard the whole story, Wheatley released Liz. But we learnt that the police would not be able to expose the criminality of Gibson/Frankton because it was an inside job.

Everything was blamed on Crowther, and Gibson/Frankton's crimes were hidden for "the national good".

Essentially, Liz was silenced for the "national interest" and the "greater good" of the UK government. Her career would continue and her family would be safe if she stayed quiet.

At the end of Protection series 1, DI Liz Nyles attended DC Paul Brandice's funeral. His death was painted as heroic - a dedicated cop who gave his life in the name of duty.

Meanwhile, DS Raj Kholi was offered a promotion in the Met - also in exchange for his silence. Liz chose a "fresh start", but whether that meant in the police or not wasn't made clear.

Is there a series 2 of Protection?

ITV has not yet confirmed if there'll be a series 2 of Protection, but it's looking very likely.

Like multiple detective dramas, including Unforgotten, Death in Paradise, The Bay, and Silent Witness, Protection has the potential to run for years.

The world of Witness Protection and the Protected Person's Unit is a fascinating one, and there's lots more to be explored. And Line of Duty proved you can never have too many bent coppers!

So long as the writing stays sharp, and viewers keep on tuning in, a series 2 and beyond could be on their way. Broadcasters rarely commission a new series until they know how the last one has done. So watch this space.

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Protection series 1 is currently available to watch on ITVX.