The star of ER and The Good Wife is back – as a doctor fighting to save humanity. She gives her bodyguard the slip to talk about our imperilled planet – and her love of Sussex A-roads

Before I meet Julianna Margulies, I spend three days staring at her bodyguard. He’s impossible to miss: one of those men whose every attempt to blend in flounders. Margulies and I are in Lille, judges at the Series Mania television festival, although our experiences differ a little. My cloak of anonymity allows me to roam the city unpestered. Margulies, however, has been a TV mainstay for 25 years, with roles in two juggernaut shows, ER and The Good Wife. Everybody knows who she is, hence Muscles.

He’s even there at the start of our interview, looming in the doorway of our room at the Chamber of Commerce. As I ease past and close the door, I ask if it isn’t a pain being constantly tailed. She smiles and says: “Three years ago, I was the guest of honour when they held this festival in Paris. When I get there, they say, ‘We have detail for you.’ I say, ‘Guys, I don’t need a bodyguard.’ But they won’t budge. We get to the hotel and I say to my bodyguard, ‘My husband and I are going out to lunch. You go home, please.’ So we left the hotel and I’ve never seen anything like it. People were everywhere. We backed into the hotel and my husband called the bodyguard and said, ‘We made a mistake!’ He said, ‘I know – I’m just around the corner.’”