Whenever we switch on our TV, or favourite streaming service, or visit our local bookshop, we're flooded with stories about spies.

Chris Costa, an intelligence officer for three decades and a former Trump security advisor, has a few theories about why this undercover world so captures the public's imagination. Today he runs the International Spy Museum in Washington DC, where he says visitor numbers keep rising.

Guest: Chris Costa, Executive Director, International Spy Museum

Producer: Lisa McGregor