The star teased: “All of the nuns are compromised when they hit the Himalayas. Sister Philippa is the one – I mean, they all go a little bit crazy because of their environment which unravels them – who is the calmest in her unravelling as it were.
“Her main problem is the beauty and mystery of the place which is taking her away from her vocation.
“Now, it’s really difficult for a contemporary audience to understand faith of that level. Nuns still exist but this is set in 1934 and there was a big reform with regards to convents and nuns in the 1960s, prior to that it was really, really strict.
“I believe that becoming a nun was a calling, so for Philippa that was something that was really close to her.”
Following her role in Black Narcissus, Bryson is going to be appearing in the hotly anticipated new series of Death in Paradise airing in 2021 and she is slated to be starring in TV series Matchmakers.
Black Narcissus airs on BBC One on Sunday, December 27 at 9pm