After the outbreak of the Russo-Japanese War (1904–1905) Ossendowski moved to Harbin in Manchuria, where he founded a "Central Technical Research Laboratory", a Russian-financed institution for development of the ore deposits in the area. At the same time, he headed the local branch of the Russian Geographic Society in Vladivostok. As such he made numerous trips to Korea, Sakhalin, Ussuri and the shores of the Bering Strait. In Manchuria, he also became one of the leaders of the considerable Polish diaspora and published his first novel in Polish, "Noc" ("Night"). He also got involved in the "Main Revolutionary Committee", a leftist organisation that tried to take power in Manchuria during the Revolution of 1905. After the failure of the revolution, Ossendowski organised a strike against the brutal repressions in Congress Poland for which he was arrested. A military tribunal sentenced him to death for conspiracy against the tsar, but his sentence was later commuted to several years' hard labour.