Jason Clarke and Patricia Arquette (Severance) are happy to have the darkness of Hulu miniseries Murdaugh: Death in the Family behind them. Happier still is Clarkes cardiologist.

To play disgraced, disbarred and incarcerated South Carolina attorney Alex Murdaugh, Clarke (Zero Dark Thirty, The Last Frontier) packed on 40 pounds.

Its something you go and talk to your cardiologist about, Clarke says in the video chat (above) for theTHR Presents series. His doctors response? Are you out of your mind? He might be. Carrying around the extra weight was just the start of it, dude, Clarke says. His physical transformation also included dyed-red eyebrows the kind you cant un-dye just to go out in public and scarf down thousands of extra calories. And at a certain point, Clarke says, the only thing that fit him were track suits.

Theres a comedy routine to it as well, Clarke says.

Despite the backaches, headaches, high blood pressure, shortness of breath, sweating and various other physical manifestations from Clarkes manifestation of the Murdaugh family patriarch, Jason was never going to actually catch up to Alex on the scale.

He was 265, dude! Clarke says. There was no way that was gonna happen!

You would be dead, Arquette says.

Though the weight is off through fasting and diet the physical fitness lags, Clarke says. He still cant do cardio not safely, at least.

Arquettes role of Alexs wife Maggie Murdaugh may not have required a massive physical transformation, but it came with its own challenges. For starters, there are all of like six words spoken by the real Maggie Murdaugh that were available for the actress to perform her accent work. Such little audio/video of her character exists that Arquette relied on Maggies sisters testimony at Alexs murder trial (for, in part, shooting and killing Maggie) to craft Maggies sounds and cadence.

Growing up as a part-time Virginian helped a bit as well, Arquette says.

Clarke had more to work with for Alexs accent in terms of source material, but the 10,000 miles of distance between Clarkes Australia and Murdaughs South Carolina negated any advantage. It doesnt help that Clarkes greatest fear is an accent going cold at go-time.

That is my nightmare of waking up with no pants on, Clarke says, walking on set and being in the middle of a massive scene or a monologue or something, and Ive got no accent.

This edition ofTHR Presentsis sponsored by Hulu.