Guest Stars Eiry Thomas as Greta Collinson Christian Patterson as Rhys Griffiths Sam Rees as Angela's Son Ashley Thomas-Evans as Greta's Son Kai Owen as Alan Kethin Ruth Madeley as Laura Tucker Phaldut Sharma as Doctor Whittaker Oliver Ryan as Sergeant Guy Hughes Silas Carson as George Byrne Clare-Louise English as Doctor Thompson Leo Ashizawa as Sora Tanaka Matthew Gravelle as Ben Christie Ioan Hefin as Ken Percival Martyn Ellis as Craig Barker