‘Don’t tell actors how to act, Mum!’: Kate Mosse on how her debut play was a family affair

‘I’ve very much enjoyed turning 60,” says Kate Mosse, tipping several sachets of sugar into a cup of takeaway coffee. It’s 9am, and the bestselling novelist and founder of the Women’s prize for fiction has travelled up to London from her home on the Sussex coast to sit in on a rehearsal of her first full-length play, staged at Chichester Festival theatre.

Across the table from her, in an unglamorous basement room that smells faintly of mildew, is the director who is helping her to transform one of her novels into a piece of theatre. And not just any piece, but a large-cast gothic revenge drama, with many mildewed basements of its own, which will open the spring season of a venue that