Clandestinos (2008)

Xabi, a troubled boy, meets Iñaki, a member of the terrorist gang ETA who becomes his mentor and ideological inspiration. Some time later, Xabi is arrested for throwing a Molotov cocktail and confined in a juvenile detention center, where he meets Joel, a Mexican, and Driss, a Moroccan, with whom he manages to flee and reach Madrid with the purpose of finding Iñaki and joining the gang.