A life-changing moment is afoot for Mackenzie Boyd in Emmerdale, with actor Lawrence Robb breaking down the discovery.

John Sugden’s vicious reign of terror continues, but Mack is onto him. When John offers him a lift in his van after a bust-up with Charity Dingle, things take a dramatic turn.

Mack finds something that completely changes his perspective on John, and potentially puts him in danger.

John, as we know, has already murdered Nate Robinson and ex-fiancé Aidan Moore, attacked Liam Cavanagh, poisoned Jacob Gallagher, and drugged mother-in-law Chas Dingle.

Speaking about Mack’s feelings about John, Robb admitted that while he hated him at first, his character’s attitude towards the villain has softened.

“He hated him when he first arrived and all the way through. He also hated him when he was with Aaron and hated him when John set him up with the slurry accident,” he shared.

“But then John twisted it and used the slurry problem to help Mack get through it all, because Mack was really, really struggling.

“So ultimately, that incident brought them a little bit closer, and Mack is now at the point of view of thinking maybe you’re not as bad as I first made out; you’re still a bit weird, but you are with my best mate, so I can kind of get on board.”

He continued: “Then of course Robert [Sugden] pipes up and has words with Mack about John and says, ‘Do you not think he’s a bit odd?’ And Mack agrees, saying, ‘Yeah, I really didn’t like him, but he’s all right now.’ I don’t think Mack and John will ever be in a position where they can go out and have a beer together. But there’s an element of understanding between them.”

This is until the “critical moment” Mack finds something incriminating for John, which Robb describes as a “mic drop”.

“That changes the entire outlook entirely,” he revealed. “It’s quite a critical moment for Mack. It is a mic drop moment. Suddenly, Mack is like, ‘Oh! You are actually…. I was right about you the whole time.'”

He said that he is “one hundred percent” of the mindset that the discovery puts him in “a dangerous position” when it comes to killer John.

“Look, there’s certainly a chance Mackenzie has the capability to bring John down,” he added. “If he does – well, that remains to be seen. But there’s potentially a very bleak outcome on the horizon.”

Despite the animosity onscreen, Rob said he had been having a blast working with John actor Oliver Farnworth, saying he’s “a lovely boy”.

“I’ve said that several times. I phoned him a couple of weeks ago, just to say how I thought he was doing such a great job, because, you know, playing a psycho like that – it is not easy. And I do think he’s doing a great job.

“And he is just the most loveliest man. It is surreal working with someone in such a relatively close proximity for a while, and to really get to know them better and to just have a laugh with them, but then do some not very nice scenes.”