APPEC (Astroparticle Physics European Consortium) and its transnational partner JINR (Joint Institute for Nuclear Research) in Dubna, the Institute for Nuclear Research of the Russian Academy of Sciences together with the Lomonosov State University in Moscow, and the Irkutsk State University are inviting astroparticle physicists and colleagues from neighboring fields to attend the Lake Baikal Three Messenger Conference. The conference will provide an opportunity to discuss how to confine nature and underlying physical processes in the non-thermal universe by making use of the three astroparticle messengers along with the multi- discipline and wavelength measurements and the theory. Scientific results achieved with current astroparticle experiments will be shown and discussed together with upcoming experimental opportunities in Russia, Europe and worldwide. A detailed look shall also be taken on capabilities of existing common analysis frameworks, alert systems, and future requirements. This conference will offer an opportunity for the astroparticle physics community in Europe, Russia and worldwide to foster the cooperation on astroparticle infrastructure projects taking data for the three messengers.