When Gabriel moves to a housing project in Södertälje, he meets Marko, who is the king of the errand boys. Marko takes Gabriel under his wing and a friendship soon develops before Gabriel realises how dangerous it is. When a spectacular mistake is made, anger is created higher up in the criminal hierarchy. Taelgia tells the story of families, police and criminals caught in a crossfire of loyalties, demands and guilt in the same neighbourhood.