Guest Stars Fiona Dolman as Sarah Barnaby Annette Badland as Dr. Fleur Perkins Hannah Waddingham as Mimi Dagmar Natalie Simpson as Erika Marx Lizzy McInnerny as Alberta Tooms Jacob Fortune-Lloyd as Gideon Tooms Keith Allen as Harry Marx John Thomson as Cooper Steinem Nimmy March as Julia Steinem Peter de Jersey as Toby Wagner Michael Nardone as Mack McInally Harriet Thorpe as Georgie Tremayne Silas Carson as Rueben Tooms Sirine Saba as Jocasta Farthing
