As Westminster grapples with the P&O scandal, a very different farce over ferries has been playing out in Scotland. In the run-up to the 2014 independence referendum, a Glasgow shipbuilder went bust and was rescued by a Scottish National party adviser. It was later awarded a £97 million government contract to build two ferries. Neither emerged. The cost now stands at £240 million and last month Scots learned that there will be another eight-month delay to the boats. What happened? Why did so much public money change hands? Was the taxpayer swindled? Those trying to get to the bottom of these questions have hit a problem common to Nicola Sturgeon’s Scotland: much of the relevant documentary evidence has vanished.