The programme is based on the terrifying true story of Dallas, Texas neurosurgeon Dr. Christopher Duntsch, who became dubbed Dr. Death after a series of devastating surgeries, which left patients maimed or dead.
Joshua stars as the title character in the show and admitted that the horrific tale was a bit much for wife Jodie Turner-Smith's mum.
"I watched it with Jodie and with my mother-in-law," he told Entertainment Tonight Canada. "Mother-in-law walked out at the end of the first surgery. Just could not… it was too much."
"Jodie kind of watched the second half of the first episode like this…," Joshua continued, covering his face with his hands. "And then the second episode was a little bit like this (peeking through her fingers), which I take to be a good thing."
Meanwhile, Jodie Turner-Smith recently attended Cannes International Film Festival to support her new movie "After Yang".
She also stars as the Queen of England Anne Boleyn in a new thriller miniseries of the same title.