Keeley Hawes 'shocked' by one major detail in new Prime Video thriller The Assassin

*The Assassin episode one spoilers follow*

Keeley Hawes was left "shocked" by one major detail in Prime Video's new thriller, The Assassin.

The Bodyguard star currently leads the cast of the highly-anticipated crime drama, which dropped in its entirety on the streaming platform today (Friday, July 25).

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The six-episode series hails from The Tourist writers Harry and Jack Williams, and centres on a former assassin named Julie, portrayed by Keeley, who has built a fresh existence on an idyllic Greek island.

However, when her estranged son, Edward (Freddie Highmore), turns up with probing questions about his father, Julie's perilous history rapidly resurfaces.

"With questions around Edward's paternity and Julie's past life as a hitwoman, the pair go on the run across Europe, working together in a fight for survival," reads the official synopsis, reports the Express.

"Along the way, their dysfunctional relationship is tested to its limits. They uncover a dark conspiracy they believe to be their only threat, but a greater danger emerges that could destroy their relationship entirely."

The logline concludes: "In a race against time, Julie fights to save Edward and salvage their relationship as past and present collide in a showdown across the globe."

Joining Keeley and Freddie in the cast are Shalom Brune-Franklin, Devon Terrell, Gina Gershon, Jack Davenport, Alan Dale, Richard Dormer and David Dencik.

Ahead of the show's eagerly awaited premiere, Keeley shared insights with Reach and other media about the dark central narrative of the drama, which is balanced by the humour between Julie and Edward.

"[In] a show like this, you need to keep the humour, otherwise it would all become very serious very quickly," she said.

In the first episode of the series, Julie takes Edward to a wedding on the Greek island, an event bustling with local attendees.

However, tragedy soon struck when armed assailants invaded the wedding in pursuit of Julie, leaving a trail of death behind them. Julie, Edward, and Luka, a local butcher played by Gerald Kyd, were the only guests to survive the onslaught.

Speaking about the unexpected plot twist, Keeley revealed that she was "shocked" when she learned about the amount of deaths that would take place over the course of the series.

"I was quite shocked at the body count... I kept thinking, 'That'll probably be pulled back', as these things sometimes are," she admitted.

"You read the scripts, it's a great idea, reads really well, and then the closer you get to it, the body count gets smaller. You have to embrace that.

"We have to see the human cost of that and that's important so it's not just literally ticking off bodies, and later on that does become a big part of the storyline, the human cost of the tragedy we see at the beginning."

Keeley continued: "There's only so much relentless action... It's important that's it's grounded in people that you care about that are not particularly likeable at first glance. You have to be rooting for them to last."

Freddie added: "It's carefully choosing which moments to lean into [the humour] or lean away from it."

Discussing the series' notable mortality rate, creators Harry and Jack shared: "We lost count of the body count, which is a new one. It's called The Assassin, people are going to die. It's always fun, particularly the opening, there's a long shot. [Julie's] got to kill a lot of people, that just felt right for this kind of show.

"I wouldn't say it carries on, it's not like exponential. There's a fair bit of death, but episode one is probably the most death heavy episode."

The Assassin is available to stream on Prime Video