Most critics come away unimpressed. The reviews describe a drab, stodgy and conventional espionage drama that does little with a promising true story, and the word “forgettable” recurs. Where praise appears, it lands almost entirely on the two leads: Judi Dench is credited with enlivening scenes the script gives her too little of, and Sophie Cookson is thought capable, with several critics finding her younger Joan the more convincing of the two.
The complaints cluster on motive. Critic after critic says the film fails to make Joan’s choice to spy persuasive, and the Evening Standard goes further, arguing that it misrepresents the real spy’s politics. The flashback structure divides opinion: IndieWire finds the past more compelling than the present, while The Guardian calls the flashbacks repetitive. The spread is narrow, with one clear dissenter: The Hollywood Reporter, reviewing from the festival, finds a taut and engaging old-fashioned thriller.
