Guest Stars Fiona Dolman as Sarah Barnaby Tamzin Malleson as Dr. Kate Wilding Andrew Lee Potts as Gideon Latimer Stephanie Leonidas as Annabel Latimer Amanda Burton as Carole Latimer Joe Absolom as Luke Altman Noma Dumezweni as Ailsa Probert Deborah Findlay as Lorna Soane Fraser Ayres as Theo Bainbridge Justin Salinger as Curate Andrew Maplin Alan McKenna as Rhodri Probert Jack Shepherd as Magnus Soane Merelina Kendall as Dr. Dorthea Grenville