The inside story of the most sensational break-up in recent political history. Once close friends and allies, Alex Salmond and Nicola Sturgeon took the SNP from nowhere to government, and Scotland to the brink of independence. Now sworn enemies, former first minister Salmond accuses some of those he once led of plotting to have him imprisoned. Reporter Mark Daly investigates and asks what the split could mean for the future of Scotland and of the United Kingdom.