Guest Stars Jack Bannon as Sam Thursday Stefanie Martini as Georgina Mortmaigne Hermione Corfield as Cassie Watkins Hugh Simon as Professor Kemp Darrell D'Silva as Geoff Craven Amy McCallum as Julia Mortmaigne David Burnett as Ricky Parker John Draycott as Turnbull Milo Twomey as Dr Hector Lorenz Ben Lambert as Guy Mortmaigne Peter Forbes as Hodges Eleanor Williams as Ingrid Hjort Rob Callender as Philip Hathaway Sam Coulson as Mark Bryden