John Maclean was a Scottish schoolteacher, and revolutionary who helped to plant the seeds of Marxism in Scotland. This is the story not just of the man, but of everything that was happening around him: from the rent strikes on the Clyde; to the Hands off Russia protests about Allied intervention against the Bolsheviks; to the twists and turns in the formation of the Communist Party of Great Britain and to the rekindling of the movement for Scottish independence.