Jodie Whittaker hadn't read the script for the entire episode of the "Doctor Who" Christmas special.
The 35-year-old actress made her debut in the festive instalment of the sci-fi series last month, and admits she had no idea how her first turn as the Time Lord would pan out, as she was just as surprised as viewers.
Speaking to the latest issue of Doctor Who magazine, which is on stands on Thursday (10.01.18), she said: "I didn't read the rest of the episode because I was only given a page to go from, which was the moment that I become the Doctor."
The former "Broadchurch" star - who will appear later this year for the full series alongside Hollyoaks" Mandip Gill, Tosin Cole and funnyman Bradley Walsh - also revealed that the colour of her trousers were chosen by herself after she suggested them to costume maker Ray Holman.
She said: "The first meeting I had about the costume was all very secret. As we were talking, I was distracted by the colour of the wallpaper behind us.
"I told Ray I loved it - and that's the colour of the trousers."
The brunette beauty has taken over the role from Peter Capaldi - who played the Doctor for four years - while Chris Chibnall has become the new show runner following Steven Moffat's exit.
Jodie previously admitted she thinks it's "f***ing brilliant" she's able to create a milestone for "Doctor Who", by becoming the first ever female to play the time-travelling alien, and has admitted it's become a "defining moment" of her life because she wants to prove to the younger generation that role models come in "different forms."
She said: "This is the defining moment of my life. I feel old enough for it. And I feel like I understand how important it is, and I'm so excited that the role models for young children, boys or girls... or teenagers, or adults, come in different forms.
"There's nothing unattainable about me. I don't look like I've been carved out of rock. I don't sound like I've had the extraordinary glamour. For me, knowing what I thought were my limitations as a person and an actor, because this industry is about, "You sound like this, you look like this"... but I'm normal."