BBC plot: Hannah arrives at Buckingham Palace, but is too late to be presented. Samuel meets two men who are interested in his invention, Denning and Mr Field. He learns that they are from MI5 and he is sworn to secrecy. The Petrukhins attend a fete at the Shaw's. Samuel invites Kathleen to attend the demonstration of the staff locator, but does not tell her it is for MI5. He demonstrates the staff locator at the military base with Courtney and Doreen from the factory, as well as Miriam, Hannah, Sacha and Kathleen in attendance. During the demonstration, Kathleen leaves suddenly in tears and Hannah runs after her. Kathleen confides in Hannah that her son Anthony went missing five years ago when he was aged 21. Kathleen goes to see Mr Spearman, a private investigator, but there have been no new developments in Anthony's case. Hannah befriends Esther, a young deaf woman who works at Samuel's factory. Hannah's etiquette teacher Nicholas persuades Hannah to take part in a civil defence ...