Guest Stars Tom Price as Andy Davidson Cush Jumbo as Lois Habiba Nicholas Farrell as Brian Green Katy Wix as Rhiannon Davies Lucy Cohu as Alice Carter Susan Brown as Bridget Spears Peter Capaldi as John Frobisher Luke Perry as David Davies Ian Gelder as Mr Dekker Julia Joyce as Holly Frobisher Liz May Brice as Johnson Madeleine Rakic-Platt as Lilly Frobisher Hilary MacLean as Anna Frobisher Aimee Davies as Mica Davies Rhodri Lewis as Johnny Davies Bear McCausland as Steven Carter Louise Minchin as Newsreader Simon Poland voices 456 Colin McFarlane as General Pierce Deborah Findlay as Denise Riley Lorna Bennett as Female Teacher Rhiannon Oliver as Mum