Guest Stars Alexandra Clatworthy as Charlotte Andrew Tiernan as Geoffrey Helliwell Fiona Button as Mary Nelson Mark Huberman as MI5 Guard William Armstrong as Ray Donovan Paul Benzing as George Gibson Daniel Hill as Headmaster Radeck Belchnerowski as Tchorek Emma Colohan as Miss Watkins Jimmy MacDermott as Dr. Phillips Mary Sheen as Mrs. Jones Jodie Hay as Student Karl Shiels as American Major David Ryan as Mr. Cranston David Hounslow as Parry-Jones Andrew Bennett as Dr. Trevelyan Robert Donnelly as Simmonds