As portrayed by Knightley, Sabina’s hysteria manifests itself in a flurry of tics, chin-juts and a burning desire to be bent over Jung’s knee and paddled until she’s blushing at both ends.

“I said yes to David before I even knew what the fuck it was,” says Knightley, cradling a large mug of tea. “Then I read it and I did kind of go, ‘Actually, I don’t know if I can do these two scenes of S&M.’ Particularly in the internet age.

“I phoned David up and said, ‘Look, I love your work but I’m going to have to turn it down as I can’t put myself through that’. And he said, ‘OK, we’ll take them out because I want you.’ Then we started talking about it…” She smiles, sips.

“Those scenes were incredibly important and the way David saw it, they were not sexy spanking scenes but something clinical and brutal…”