Riga, 1906. Professional revolutionary and skilled conspirator Jan Luther-Bobis (named Adolf Carlson in the film), whose activities have long been known to the secret and city police of Riga, is very talented in hiding, posing as a flax merchant. During one of the raids, Carlson is nevertheless arrested and put in a cell in the pre-trial detention center of the Police Department. Here, with the help of all sorts of bullying, they are trying to knock out information about a revolutionary organization operating in Riga. Carlson's comrades make a daring armed attack on the Police Department and free him. After some time, Carlson, under the guise of a respectable gentleman, leaving for the next task, calmly leaves Riga.
—from the Annotated Catalog of Soviet Feature Films