The Assassin is the delightful mother-son espionage treat we never knew we needed.

The Assassin is one of those rare gems that sneaks up on you.

Kind of like a menopausal James Bond would sneak up on her enemies in the dark, slowly but surely, until suddenly she attacks — catching you off guard with an unexpected twist.

When I first sat down to watch the new six-episode series on Stan, I had my reasons. And I suppose you could say they were vaguely 'personal' or something.

The Assassin whimsically asks the question: what if your mother was a retired assassin and you had absolutely no idea? And now you're on the run, but you're really not built for this life of espionage and murder and hijinx?

As someone whose own mother continually tells her she "wishes" she was a spy, I must say I was intrigued. I'll never live out this moment for real — and thank God, because I hate running — but at least I can enjoy watching the chaos of such scenes unfold on-screen.

The new Stan Original Series comes from the minds of Harry and Jack Williams — who previously brought us The Tourist, Boat Story and The Missing. And it's led by a divine duo: Keeley Hawes (The Bodyguard, Line Of Duty) and Freddie Highmore (The Good Doctor).

Freddie Highmore and Keeley Hawes star in The Assassin. Image: Stan.

Julie (Hawes) is a retired assassin living on a picturesque island in Greece, where she seemingly enjoys her peace and quiet by literally ignoring everyone else in town. Which is relatable, in its own sense — as relatable as an assassin can be.

When her son Edward (Freddie Highmore) comes to visit, her personal life is thrown into disarray as he pokes and prods to find out how he inherited a mysterious fortune on his 30th birthday. Was it from his father, whose identity remains unknown? Who could say! But he's sure going to annoy the heck out of his mother as he asks endless questions.

As Julie and Edward bicker, fumble their conversations, and attempt some semblance of a normal mother-son relationship, there's another spanner thrown into this powder keg of a situation.

Julie's former 'handler' calls to recruit her for one more job near the island. But when the mission turns into something far more sinister (yes! Even more sinister than an assassin simply killing someone!) the mother-son duo must escape the island and flee for their lives.

All while trying not to kill each other out of sheer frustration.

"Julie's not a stereotype. That's one of the things that was so appealing, to me, is that I really believe that this woman existed," Keeley told Mamamia of taking on the role in this high-octane action dramedy.

"And it was sort of a secondary thing, actually, that she had been an assassin rather than it being her entire personality. And what was most important, actually, was the relationship at the heart of it between this mother and son, which is quite unusual to see. It's a nice road to go down for our central story."

Freddie echoes her sentiments, saying the unexpected dynamic was what drew him to the part.

"There's the high stakes that Jack and Harry [Williams] do so well — and I loved The Tourist. But at the same time, really what the show is about at its heart is just this mother and son duo, who have this complicated, messy, slightly estranged relationship and I think at the beginning they aren't able to get past that, even though deep down they are closer to each other and somewhat similar, more similar as people than they would like to admit," he tells Mamamia.

"There's the Trojan horse of the fun, thrilly, splashy stuff, but really the relationship feels like the heart of the show. And doing so with that great dose of British-Australian humour, that I think makes it feel very grounded and real and genuine as opposed to too elevated and silly.

Aussie Alan Dale stars in The Assassin. Image: Stan.

As for their on-screen banter, the pair reveal it didn't take much for their witty quips and one-liners to flow naturally.

"When people say we worked [on our relationship], I don't feel like we ever sat down and were like, 'okay we really need to try and make this work'. It just felt like there was an innate connection from the beginning. I think we have a very similar sense of humor, that was something we could just lean into," Freddie said.

"It just feels very much like we had already worked together," Keeley added. "So it couldn't have been more natural and organic. There's nothing worse than having to work on a relationship or to try to create chemistry if it's not there. We just sort of had that in spades, and it was sort of miraculous, really, because it's so important to the show."

The show leans heavily into witty, dry humour that jolts you back into the very human storylines at the centre of all the stunts, gun-fights and action. And yes, at one point in the series, Edward does refer to his mum as a "menopausal James Bond," so I wasn't exaggerating before.

"I don't think the humour is dark humour, but you don't necessarily laugh out loud at it — it's like always there, and adds a sort of nuance and texture, and, and keeps it real," Keeley said of their banter. "And I think that was the balance of finding it in a way that doesn't completely undercut the tension of the scene and the drive of the episode, but just gives you more of an insight into the two of them."

As the pair escape a devastating tragedy and close-call on Julie's island, they traverse the European continent in search of answers, uncovering a dark conspiracy surrounding Julie's latest mission and Edward's paternity.

It's impossible to tell you much about the rest of the cast without leading you to spoilers, so I'll say this: the show features a fantastic ensemble of actors, including the legendary Gina Gershon, Jack Davenport, Gerald Kyd, and Australia's own Alan Dale, Shalom Brune Franklin and Devon Terrell.

There is also a whole host of side characters who exist simply to throw us off track, too, and that's half the fun.

As we flit between competing storylines, different locations, and increasingly high stakes, with an unending number of twists on our doorstep, it's clear the goal of The Assassin is simply to surprise and delight and, in its own way, make us feel seen for the messes we all are.

I saw one review that claimed The Assassin went beyond the realm of 'reasonable storytelling' and to them I say, 'maybe you should watch a documentary'.

Watching a dysfunctional family solve a criminal mystery can in fact be a delightful viewing experience. Even if you don't find it plausible — I mean, I don't recall the last time someone asked if Die Hard was real.

It's a thrilling, suspenseful action series that manages to bring warmth and laughter to the forefront, while still remaining twisty and seemingly unsolvable up to the final moments.

The Assassin is an entertaining ride that will keep you enthralled throughout your weekend binge-watch.

"I think it's really relatable," Keeley tells Mamamia. "I love that it's so honest and there's nothing saccharine about these two. They know each other down to their bones, you know, nobody knows either of those characters better than they know each other. 

"I totally believe them, as a family and, you know, whose family isn't dysfunctional, to be honest? The most important thing is that the whole time, we are rooting for their relationship to work. You know, we can see a world in which — even if they can't initially — where this could be a lovely thing.

"Julie and Edward have been pushed to their limit, and I think it's fun to explore these characters when they are at their most heightened or vulnerable or energised, for whatever reason, and that's what we get to do over the course of the show."

The Assassin is now streaming on Stan.

Feature Image: Stan