Judi Dench stars as an ex-spy with a secret past in this British drama directed by Trevor Nunn. Based on real events, the film begins with the arrest of Joan Stanley DenchSophie Cookson, an octogenarian living in London accused of treason. After being brought in for questioning, Joan's secret life as a KGB spy is exposed. While studying physics at Cambridge in the late-1930s, Joan falls in love with Jewish refugee Leo Galich Tom Hughes and finds herself drawn into his communist activism. When the Second World War begins, Joan is hired to assist Professor Max Davies Stephen Campbell Moore on a top-secret government project but finds her loyalties severely tested.