Aristocrat Lieutenant Beamish Cooke-Cooke is brought in by Irving and his army to instill discipline.
Lady Gertrude offers to help out Irving by tracing his ancestors, but she soon discovers something amiss in his genealogy.
Irving and the platoon grow suspicious of Rossi's secret assignations.
Town clerk Randall Todd organises a Brains Trust at the church hall, and challenges the Americans.
When some essential commodities go missing, the culprit, Rossi, is ordered by Irving to appear before the unit psychiatrist.
Rossi and Doreen are getting married, but when Irving makes a mistake, he must stop the wedding.