During a Christmas party, Euphemia Martins – together with Bertram Stapleford and manservant Rory McLeod – is tasked by the slippery government agent Fitzroy with doing a little snooping at the Staplefords’ Highland Lodge.
When Euphemia discovers the purposes of the charade for which she has been demoted back to a maid, she is furious. There are plans afoot – plans which involve signing the Official Secrets Act …
Meanwhile, Rory still isn't speaking to her and Bertram is more interested in growing his awful new beard. The arrival at the Lodge of four mysterious 'Mr Smiths' – and some outrageous proposals for Scotland’s future – raises tensions to boiling point, and that's not even mentioning the German spy lurking in the woods, or the accident with some hot soup …
But when the inevitable dead body turns up, they must all work together or find themselves jailed for murder.