It was Scotland's worst outbreak of a deadly superbug which claimed the lives of 18 patients in just one hospital earlier this year. For the first time, using leaked documents, eye witness accounts and whistleblowers, BBC Scotland Investigates what really happened at the Vale of Leven Hospital. We discover the official death toll of 18 could be much higher, and the outbreak could have been avoided if Scotland had learned lessons from south of the border. Investigation's reporter Samantha Poling also uncovers disturbing evidence which suggests a similar outbreak could happen again, at another Scottish hospital.