Sinn Féin is the most popular political party in both Northern Ireland and the Republic. A movement once synonymous with a paramilitary campaign is on the brink of taking real power through purely democratic means. But if Sinn Féin has mastered the art of electoral politics, it remains strangely opaque. Who really runs the party? How is it funded? And what can we expect of it as a party of government? (13th September 2023)