Guest Stars Richard Durden as Conor Hodgson Daniel Weyman as Max Thorndyke Julia Haworth as Rosie Chamberlain William Ash as Major Mark Sealy Clare Higgins as Professor Katherine Dukes Ben Bailey Smith as Lieutenant Colonel Ben Carmichael Graham Turner as Arthur Simpson Tina Chiang as Simone Taylor Ash Tandon as DI Karl Guyatt Will Stevens as Private John Sealy Michael Simkins as AC Harry Lennox Caroline Lee-Johnson as Sandra Gibbs Daniel Parr as Edmund 'Fish' Fishbourne