Enrico Malatesta (Eddie Constantine) leads a group of Latvian dissidents in the siege of Sidney Street. Chief of police Winston Churchill organizes against the anarchist who threaten to disturb the peace to make their demands known to the British aristocracy. Authorities break up the volatile gang and Malatesta is deported to Italy. Constantine gives a sympathetic portrayal of the agitator that organizes the revolt that shocked the Edwardian sensibilities of London in this historical drama.