Casualty spoilers: Olly Rix makes his shock debut as Flynn Byron, while Stevie suspects she's pregnant!

Olly Rix as Flynn Bryon. Close up shot of Flynn checking on an unconscious woman in a road.

Olly Rix makes an unforgettable entrance as army medic Flynn Byron in Casualty episode Everything Changes. (Image credit: BBC Studios.)

Olly Rix's arrival in Holby as army medic Flynn Byron heralds the dawn of an era of change in Casualty.

This week, special episode Everything Changes - the first instalment of the new 12-parter Internal Affairs - largely focuses on Flynn, as he’s caught up in a traffic accident that changes the course of his life and eventually results in his appointment as Holby ED’s latest clinical lead.

But the military man isn’t the only character in the spotlight when this nail biting episode airs on BBC1 on Saturday 15 March 2025 at 8.30pm (See our TV Guide for listings).

Consultant Stevie Nash wrestles with a life-changing development, nurse Jodie Whyte attempts to get closer to Dylan Keogh, and new light is shed on junior doctor Tariq Hussein!

More Casualty spoilers for Everything Changes below…

Introducing Olly Rix as Flynn Byron

Olly Rix makes an impactful impression as Flynn Byron in Casualty this week when the Call the Midwife and Our Girl star's first episode opens with the army medic caught between two worlds.

We initially meet him at home with his family, where it’s revealed that in five days' time, Flynn is due to be deployed 3000 miles away for six months.

Yet, despite having precious little time to spend with his wife Claire (Elisabeth Hopper, Home Fires) and daughters Millie and Poppy (played by Elsie Antonia Maurice and Lola Grace Maurice), he’s distracted and detached as he prepares to leave them.

After a restless night, Flynn is further unsettled when he receives a series of incessant phone calls…

Claire and Byron talk at home. In the background you can see their sunlight home set up with balloons and streamers for a child's birthday party. — Claire's concerned Flynn is going to break his daughters' hearts... (Image credit: BBC Studios.)

A hasty exit

While Claire and the girls are busy preparing for Poppy’s birthday, Flynn makes a flimsy excuse to leave under the guise of getting some last minute presents and promises to be back in time for his daughter’s party.

Instead he meets with Captain Amber Mitchell at a bar, and it quickly becomes clear that the pair are more than colleagues.

Although Flynn is initially hostile towards Amber (Sophie Melville, The Pact), attraction sizzles and she persuades him to have one drink with her…

Amber sitting in a dark dive bar with orange brickwork in the background, dressed in a bright red blouse looking longingly at Flynn, who is off screen. — Red alert. Amber is the other woman! (Image credit: BBC Studios.)

A deadly decision

With the clock ticking, it becomes apparent that Amber is several sheets to the wine and, although he's keen to get going, Flynn gives her his jacket and offers to drive her home.

As he’s winding his way through country roads, Flynn lays it out to Amber that his work life and home life must remain separate. An argument ensues, followed by a dangerous decision that results in a terrifying traffic accident, leaving them both fighting for their lives!

Flynn makes a split second decision to drive Amber home... (Image credit: BBC Studios.)

“When the collision takes place, the episode switches from conventional filming to point-of-view and you get to see who Flynn really is,” Olly Rix tells What To Watch in an exclusive interview. “From the way he reels off information to ambulance call operator, Indie [Naomi Wakszlak], to doing multiple things at the crash site in a calm and collected way. He’s covered in blood and an absolute mess yet, even on death's door, he’s making clinical assessments about what's going on around him.”

Eventually, paramedics Jacob Masters (Charles Venn) and Iain Dean (Michael Stevenson) arrive on the scene and whisk the casualties to the ED, where the drama is ramped up further in this terrific point-of-view storyline.

Full interview coming soon. Spoilers continue below.

A point of view image from Flynn's perspective of paramedics Jacob and Iain in their uniforms looking at him with concern by the side of a road. — From this point on viewers will see much of this episode from Flynn's perspective. (Image credit: BBC Studios.)

Is Stevie Nash pregnant?

Just as one of Stevie’s secrets is blown, there’s another one waiting in the wings!

In the previous episode Just Like You it became public knowledge that Stevie Nash (Elinor Lawless) was in a relationship with Siobhan McKenzie’s husband Rich Walker before he died. This week, Stevie is faced with an altogether different dilemma.

The consultant starts her shift feeling green around the gills and throwing up in the work toilets. She’s also extremely tetchy, which an undeserving Cam Mickelthwaite (Barney Walsh) soon finds out! But, as of yet, she's not prepared to face what this might mean.

Stevie Nash at work wearing her blue uniform with her stethoscope around her neck looking tired and upset. — Stevie refuses to pause for thought. (Image credit: BBC Studios.)

Instead Stevie ploughs through a busy shift, working alone where possible, until events take a dramatic turn with the admittance of Flynn and Amber.

From that moment onwards, it’s all hands on deck as Stevie and Dylan lead the team in saving lives.

And, intriguingly viewers discover that Flynn knows Stevie, but due to the severity of his injuries, she doesn’t recognise him. How are they connected?

Later, after the life or death shift, Stevie finally decides to takes a pregnancy test… Is she expecting Rich’s baby?

Head shot of Flynn in a hospital gown being wheeled to surgery on a trolly. He's wearing a mask for breathing and his face is covered in cuts and bruises. — Initially Stevie doesn't recognise Flynn. (Image credit: BBC Studios.)

Also in Casualty this week

At the beginning of the day, senior medic Dylan Keogh (William Beck) draws junior doctor Tariq Hussein (Manpreet Bachu) aside and delicately - or at least as delicately as possible for Dylan! - tells him that he needs to pull his [surgical] socks up and start proving himself.

As the episode unfolds a silent, helpless patient witnesses a catalogue of mistakes which may have far-reaching consequences for Tariq’s patients…

Dylan has a quiet word with Tariq about his work ethic or lack thereof... — Dylan has a quiet word with Tariq about his work ethic, or lack thereof... (Image credit: BBC Studios.)

Junior Doctor Nicole Piper (Sammy T. Dobson) is on surgical rotation working alongside surgeon Russell Whitelaw (Robert Bathurst).

Meanwhile, Russell is utterly stunned when his son-in-law Flynn ends up on his operating table. Will he twig that Amber is Flynn’s affair partner?

A point of view image of Russell from Flynn's perspective, where the surgeon is looking down at him with a grave expression on his face. — Russell realises his daughter's happiness is in his hands. (Image credit: BBC Studios.)

Newly engaged Faith Cadogan (Kirsty Mitchell) looks forward to an evening at home with her fiancé. You did good Iain Dean!

Faith Cadogan at work, staring into the distance with a smile playing on her face. — Daydream believer. It's starting to sink in for Faith that she's going to become Mrs Dean! (Image credit: BBC Studios.)

Rida Amaan (Sarah Seggari) is feeling the love from new boyfriend Sean Redmond (Seth Somers).

Jodie dressed in a black denim jacket about to leave the ED after her shift, stops to talk to Dylan. — Jodie appears happy for Rida, but why is she reaching out to Dylan? (Image credit: BBC Studios.)

Dylan realises that Ngozi Okoye (Adesuwa Oni) lives with a private struggle. How will she react to the doc finding out about her personal secret?

Dylan at work, looking perplexed. — Will Dylan keep his distance from Jodie? (Image credit: BBC Studios.)

And, finally, Jodie Whyte (Anna Chell) has something to celebrate. Will Dylan accept her invitation to join him after their shift ends?

Flynn standing in the ED smiling. — Meet Flynn: A husband. A cheater. A hero. A secret keeper. And destined to become Holby ED's new clinical lead... (Image credit: BBC Studios.)

Casualty episode Everything Changes airs on BBC1 on Saturday 15 March 2025 at 8.30pm. The episode is available on BBC iPlayer from 6am.

If you are affected by any of the storylines in this week's Casualty, please know that help, support and information is available from BBC Action Line: https://www.bbc.co.uk/actionline/