Cambridge, 1932. Maisie accepts her first formal intelligence assignment and enters a private college as a lecturer, instructed to observe political activity that may threaten the government. The institution was founded around pacifist ideals, but its students and staff include advocates of authoritarian movements gaining support across Europe.
When the college principal is murdered, Maisie must continue her covert work while investigating a death that Special Branch would prefer to treat as a separate matter. The inquiry reveals how war weariness, class privilege and economic fear can be exploited by fascist organisations, and how easily a declared commitment to peace can conceal political extremism.