The article notifies the significance of the cultural dialogue which has the history of four centuries, the dialogue between Prussian Lithuania and Lithuania Proper. Taken into account are the peculiarities of ethnic formation of both areas, as well as different strategies of assimilation policy used by Prussia and Russia. Consequently, these different strategies were accepted differently and yielded different effect. The activity of two cultural societies, that of Litauische literarische Gesellschaft, and that of Birutė is taken for comparison in the aspect of rising Lithuanian national self-consciousness, and the emphasis is laid upon sociopsichological aspects of the dialogue (which was not always direct) rather than upon historical or cultural parallels. To refresh run-of-the-mill academic attitude and discourse, unconventional literary means of the detective genre are put to use as a compositional and stylistic instrument.