Over the past two decades, there have been notable changes in North Korean migration: from forced migration to trafficking in women, from heroic underground railways to people smuggling by Christian missionaries. The migration has taken mixed forms of asylum seeking, human trafficking, undocumented labour migration and people smuggling. The paper follows the footsteps of North Korean migrants from China through Southeast Asia to South Korea, and from there to the United Kingdom, to see the dynamic correlation between human (in)security and irregular migration. It analyses how individual migrant’s agency interacts with other key actors in the migration system and eventually brings about emerging patterns of four distinctive forms of irregular migration in a macro level. It uses human security as its conceptual framework that is a people-centred, rather than state- or national security-centric approach to irregular migration.