Fast forward to this week’s visit to Holby City and the actor’s wish comes true in rather spectacular fashion, as his fan-favourite character discovers he’s about to become a father on the same day he’s arrested on suspicion of manslaughter by gross negligence.

“Between the last time we spoke and now, I’ve been careering through this bizarre life that Dylan’s leading,” smiles William, 48, when he joins us for another exclusive interview. “It would be foolish to pretend that I’m not thrilled – it’s been great to get my teeth into!”

Here William, who joined the BBC1 medical drama in 2011 and is the longest serving current cast member, shares his case notes on Dylan’s dramatic change in fortunes…

This sounds like an unmissable episode for Dylan fans. What did you think when you first learned about the double whammy of the pregnancy and arrest storylines?

“The fact that they follow so hot on the heels of each is a jarring and dramatic spoke in the wheel. I’m always looking for a wave to surf and this one’s amazing. All of a sudden these two storylines are united and you get a sudden burst of Dylan!”

How does Dylan initially react when his girlfriend, psychiatric liaison nurse Sophia Peters, reveals she’s pregnant?

“‘Bolt from the blue’ would be the best way to describe it! I remember when I was filming these scenes with Kellie Shirley, who plays Sophia, there was a ricochet of different feelings from Dylan that she misunderstands. You can see a disagreement happen before they go their separate ways [when work duties stop the conversation short], but it’s not really a disagreement, just that communication is lacking. Dylan and Sophia are a couple who probably don’t do a huge amount of pillow talk and it becomes this perfect storm of misunderstanding.”

Their romance is relatively new. How would you describe their dynamic at this point?

“Dylan is someone who approaches any relationship with caution, and Sophia took a novel approach to charming him, so he was sort-of alarmed by her abruptness. She’s also someone who’s cautious, however, and the reality is, they don’t know where they are with each other a lot of the time.”

He’s not exactly known for being a cuddly character. What sort of father do you think Dylan would make?

“Dylan’s definitely an optimist, even though he disguises it and, I think, once he has time to absorb the thought of it, he’d be positive. Although he qualifies as an older dad I’d imagine he’d go at it full pelt, but he’d find it boring until the child could learn the periodic table! Practically, though, he’d probably be very capable and without question it would dimensionally change him. It would be fascinating to see.”

How shocked is he to be arrested on the suspicion of manslaughter by gross negligence?

At the start of the current miniseries, Public Property, Dylan was unable to help mum-to-be Thea after the car she was in drove into a restaurant, but he did save her baby, Elsie.

“When we first come into this episode it’s a really confusing time for Dylan, because he doesn’t know what’s happening with the complaint from Aaron Bayliss [Thea’s widower and Elsie’s dad, played by Jack Wilkinson]. To Dylan it’s completely ridiculous – he knows he’s done nothing wrong, so this is the last thing he expects.”

We can reveal that next week’s Casualty picks up directly after Dylan’s shock arrest. Can you tease what happens when he’s interrogated at Holby Police Station?

“Seeing him under arrest is almost like a standalone episode in terms of how it hits him. Everything crashes down and nobody will believe that he hasn’t done anything wrong. There usually isn’t really an opportunity for me to escape the paddock because Dylan is, by and large, hospital bound. But this next episode was all shot in real police holding cells in Cardiff and you can just imagine going completely bananas in there if you knew you’d done nothing wrong.

“Dylan’s indignance and his intransigence about the fact that what he did [in saving baby Elsie] was right, is so total that he’s reeling and feels the most incredible frustration. He’s confused at how it could come to be that Aaron has made this allegation…”

Which brings us neatly to nurse Jodie Whyte (Anna Chell). We know that Dylan will discover that she slept with Aaron and led the grieving journalist to believe that he may have made the wrong life and death choice at the crash. Can we expect fireworks when he finds out the truth?

“Yes, it’s like Dylan’s been scalded and you will see him have an almost visceral response when he realises. It’s a really complex reaction, because there’s betrayal and judgment, but also responsibility because he promised Jodie’s father Max Cristie [played by Nigel Harman, who departed the programme in March 2024] he would keep an eye on her, but I don’t think he knew what he’d taken on!”

“There’s so much undiscovered in Jodie’s character and background and I know that the story is going to follow her for a good few episodes and I’m not sure how brilliantly he deals with the complications of being a middle-aged white man in the 21st century! When it comes to Dylan’s interaction with Jodie it’s a bit like The Hurt Locker, where he needs a different approach to each defusing and unfortunately, she goes off once or twice!”

You’ve been playing Dylan since March 2011. Do people often confuse you for being just like him?

“Oh it happens all the time! It’s the remarkable effect of being associated with one job for 13 years. When I say that I’m not like Dylan, I couldn’t mean it more. Yes I went to medical school, but thankfully I immediately realised my mistake and I think the medical profession should breathe a heavy sigh of relief about that!”

We’re very excited to see how these must-see storylines pan out for Dylan. Even though you know how they unfold, will you watch the episodes as they air?

“I will, but with a degree of reluctance because it’s hard to get over the shock of seeing yourself on telly – and it gets worse the older you get! But I need to know what I’m doing right and wrong on-screen because I feel accountable for Dylan. I’m looking forward to watching how everything explodes over the coming weeks! The cards are thrown up in the air and I don’t think anybody knows which way they’re going to fall. And if you think these storylines are impressive, wait till you see the things that I’m shooting at the moment!”