In an interview with the Scottish Mail on Sunday, Labour leader Ed Miliband is quoted as suggesting the "stark threat" (in the paper's words) of manned border posts between an independent Scotland and England in the event of the two countries having different immigration laws.
As a new poll put the 'yes' camp ahead (51-49, excluding those who are undecided) for the first time with only 11 days until the independence referendum, Mr Miliband told the paper: "If you don't want borders, vote to stay in the United Kingdom."
When asked if this would include border guards, the Labour leader added: "It would have to be looked at."
This "incendiary" (in the Scottish Mail on Sunday's words) plan got the paper very excited, and they even mocked up a map where the border could be policed.
However, Labour has poured water on the paper's splash, calling it "ridiculous".
So, there you have it: Ed Miliband doesn't want border guards between Scotland and England because he wants to preserve the 300-year-old Union.
And there might be no proactive Labour "plan" for a manned border between the two countries, but if an independent Scotland joined the European Union's Schengen Area (a group of 26 countries where passport or border control has been abolished), some form of England-Scotland border control would probably have to be reintroduced.
Clear as mud.