"Home Guard and Mumps" is set in the mid-1940s, the farmer Nils Erik Kristersson (Stefan Gerhardsson) farm at Ätran in Falkenberg. He is married to the ill-tempered Mathilda (Siw Carlsson), and together they have daughter Greta. The farm is also home to the försupne toffelmakaren Ola Larsson (Krister Claesson) and the bleating maid Emma (Tina Leijonberg).  The farce begins with the second lieutenant Löwendahl (Tommy Juth) and Sergeant Malmberg (Gosta Janson) shows up in the yard to announce that they intend to use the farm for the Home Guard.