Lock-Down Estate

Scotland, 1930s. The ancestral estate of Loch-Dawn has been home to the bickering and resentful Inverkillens for over 600 years. The family's fortune has significantly diminished over the past centuries, and they are forced to engage in undignified activities for... aristocrats: selling salmon and producing poor-quality whiskey. However, none of this helps, and to top it all off, the body of the 19th Earl is found in the river with a crushed head.
The investigation is entrusted to the unlucky Inspector Jarvis, who quickly dismisses the incident as an accident. After all, in small towns, crimes don't happen, only fights in pubs. The only one who disagrees with this conclusion is the observant housekeeper, Mrs. MacBain. She knows far more secrets about the noble family than anyone else. She is convinced - a murder has occurred, and the murderer is hiding in the house right in front of everyone.