Wading into the cold Atlantic ocean, waves crashing over her head, her lips slowly turning blue, there were moments when Jessica Brown Findlay feared for her life.
The actress known around the world as Downton Abbey’s elegant Lady Sybil found herself gasping for breath as she filmed the BBC’s gritty new three-part adaptation of Daphne du Maurier’s Jamaica Inn.
Yet despite the danger and discomfort, she was having the time of her life playing headstrong Cornish girl Mary Yellen.
“Filming in the sea was ridiculous,” she tells me, she tells me with her distinctive, throaty laugh.
“It was exhilarating and special because you were able to get to a place so far beyond where it feels ‘pretend’. It was very real and there was a certain level of fear. You were in the sea, everyone disappeared and you may drown.
“The waves were so big – you’d go under and for a few seconds you couldn’t see which way was up.”
Jamaica Inn runs on BBC1, on Easter Monday, Tuesday April 21 and Wednesday April 22