On New Year’s Eve of 1910, St. Petersburg's aristocracy and middle class celebrate the dawn of a new decade, while the revolutionary underground continues its struggle.

Among them is the aging revolutionary "Polivanov," also known as "Sedoy," who moves between clandestine locations, encountering a mix of loyalty, cowardice, and outright betrayal.

By spring, three comrades from the working-class Narva District—Maxim, Dema, and Andrei—rescue an underground activist, Natasha, from a police informant.

Later, Maxim is released but is forbidden from living in most European provinces of the Russian Empire (a scene missing in many versions of the film).

Tasked by the Russian Social Democratic Labour Party (RSDLP), Maxim adopts the alias Pavel Agafonovich Malakhanov and heads to Nizhny Novgorod to support the struggle of the Sormovo workers.