In February 1918, the Russian ship Orion, carrying weapons for two divisions, is delayed in Plymouth due to the Russian Revolution. The British order it to Arkhangelsk, but it secretly sails to Vladivostok. Pursued by the British, a German submarine, and with a divided crew, the Orion raises the red flag upon reaching Russia. However, Vladivostok is controlled by interventionists, so the ship fights back to sea and delivers weapons to coastal partisans.