Guest Stars Ruth Bradley as Sarah Sellars Eleanor Fanyinka as Cecily Fenner Elliot Levey as Ray Jubba Andrew Havill as Professor Lucius Stamfield Julian Moore-Cook as Jack Swift Christopher Brand as DS Bill Shaw Joseph Millson as Robert Fenner Harriet Thorpe as Miss Newell Evelina Jarrebring as Brigitte Eriksson Roxanne Palmer as Frida O'Rourke Angus Yellowlees as John Sarson Gabriel Tierney as John Paul Martinelli Mia McCallum as Maggie Widdowson Killian Coyle as George Sellars Tom Spink as Noel Baxter Jacinta Mulcahy as Mrs Swift Colum Convey as Marmaduke 'Duke' Ward Lewis MacLeod as Eamonn Andrews John Hollingworth as Dan Lofthouse