Back in Action ending explained: Director unpacks final moments

"Jamie Foxx had an early inkling that there was a glimmer of hope," he said about convincing her to take part. "He didn't bring it up in our first conversation, but soon after that, it was brought up to me and my reaction to that was like, 'I thought she was retired? That's what everyone has told me.' But they're old friends, and I think he knew there was a possibility that she'd be open to reading something."

Eventually, she agreed to read the script – and when she appeared to be game, Gordon said it was a "no-brainer" to cast her, adding that "I don't think anybody can do action and comedy like her."

The character she plays is Emily, a former CIA Agent who is now living a domestic life with husband and fellow ex-spook Matt (Foxx) and their two children fifteen years after leaving the CIA. But soon, their ex-handler comes knocking at their door to inform them that some rather brash behaviour while trying to prevent their teenaged daughter Alice (McKenna Roberts) from attending a club night have alerted some old enemies to their whereabouts.

As a result, they must return to action in a plot concerning a missing key that takes them to London and sees them encounter Emily's estranged mother Ginny (Glenn Close) – who is also a former agent – and her much younger romantic partner Nigel (Jamie Demetriou).

Wondering how it all ends up? Read on for Gordon's insights into the ending, including what a late reveal might mean for a possible sequel.

Back in Action ending explained: Director unpacks final moments

One of the first big reveals in the film comes towards the half-way mark, when it emerges that Emily and Matt's former handler Chuck (Kyle Chandler) has double-crossed them, and had actually been the man behind the whole ordeal – it was him who was really after the key.

Before we are directed to the true culprit, Chuck had explained that Andrew Scott's MI5 agent Baron was the real bad guy, and Gordon revealed that the casting was very deliberate as far as both actors were concerned.

"They were both sort of cross cast, in a way," he explained. "Kyle Chandler, I feel like what he's best known for, probably, is Friday Night Lights, which is this, 'Aw shucks', good guy. So I don't think you see him.... you don't often see him in comedies, but you definitely don't often see him as the villain, so I thought [he was] perfect for that surprise."

He added: "And I think Andrew Scott's just one of the best living actors. He's just amazing. And I felt like it was the perfect choice for someone who would be sort of a red herring, [you] thought [he] might be the bad guy... it turns out he's not, but he's a little annoying, right?!"

After the reveal, Chuck takes the kids hostage, and Emily and Matt are forced into a major showdown that begins at London's Tate Modern Gallery and spills out onto the streets – and even the Thames – nearby. It's a high-octane sequence that includes motorbikes, speedboats and, at one point, Jamie Demetriou's character Nigel emerging as an unlikely hero, and Gordon was delighted to get to shoot it at his first choice of location.

"Architecture is my degree, and the Tate Modern is a place I studied before I got the chance to visit it," he explained. "Every time I came to London, it was a bit of a pilgrimage. Just, it's so awesome. I mean, it's weirdly like a church, you know, that enormous nave that I think was the boiler room."

He continued: "It was an insane thing to put in the script, because it was such a long shot that we could possibly shoot there. And it was just a stroke of luck that our location manager knew somebody from way back, who was working there and it worked out. I thought for sure we were going to have to re-conceive it and put it somewhere else.

"[But], like that was a critical, I really wanted to chase down the Thames. I wanted the barriers... It's just a natural place to start that chase from, and it's such a phenomenal landmark."

Gordon also explained that putting together the sequence was an "elaborate" process, especially since the character of Nigel wasn't even in the original script and they ran into a few logistical issues while filming.

"There [were] Tate availability issues," he said. "Like, we only could be there so many nights, and we had to move in every night at 8pm and be out by 4am and we'd move everything in and everything out every night. So there were just a lot of restrictions.

"So that confrontation was originally written to be in the Tate where he stops Daphne, but instead, we staged it outside... it's like one block away and gave him that big heroic moment. And I just thought Jamie played it perfectly. It was just hilarious."

After the sequence finishes and the villains are safely dispatched, the film ends with all three generations of Emily's family reconciling – and for Gordon, this should be the main takeaway for viewers at the end of the film.

"That I feel like is the core story point, and the thing that catches people by surprise," he said. "You know, the film's got the heart and that family story arc, and that was really born out of some experiences with my own family where something I'd witnessed in my dad's behaviour confused me, but then, when I was old enough, I saw in his interaction with his mum, 'Oh, that's why such and such thing happens.'

"Like it only was around, you know, the kids age in the movie, when I myself was able to appreciate the impact that the older generation... what their relationship must have been, and maybe how that explains why they're behaving the way they are now.

"And I felt like that was the perfect kind of light bulb for Alice to have given her frustrations with her mum in the movie."

Does Back in Action set up a sequel?

After their safety has been secured, there is one last twist in the film – and one which appears to set up the possibility of a sequel. Back in the States to resume their domestic life and put espionage on the back-burner once again, Emily and Matt get into their car only to find Baron waiting for them with word of another mission, which seems to have something to do with Emily's father. And this is something that takes Matt very much by surprise.

Speaking about that final twist, Gordon explained: "Baron was someone we added to the end of the movie, and that was about scheduling and availability, actually. And so it felt like he should be there, trying to draw them into some other case. And then the notion of 'dad' was born out of that.

"Like you haven't brought up dad, but clearly Ginny was an interesting character back in the '70s. So who was she seeing, you know? That was our... that was the sort of instinct underneath it. And we toyed with whether or not to leave that in as a tease. And I'm really glad we did. I think it gets people to lean in."

Asked to expand on whether he was already planning a sequel, he added: "Oh yeah, [I've] got some ideas about what it would be about and who could play the part, but, you know..."

We'll just have to wait and see!

Back in Action is now streaming on Netflix.

If you're looking for something to watch tonight, check out our TV Guide and Streaming Guide or visit our Film hub for all the latest news. For more from the biggest stars in TV, listen to The Radio Times Podcast.