Guest Stars Caroline O'Neill as Win Thursday Abigail Thaw as Dorothea Frazil Sara Vickers as Joan Thursday Adam James as Kent Finn Gillian Saker as Dr. Pat Amory Katherine Kingsley as Mona Davies Geff Francis as Grantly Smalls Tristan Sturrock as Dr. Bernard Gould Chris Fulton as Dr. Broderick Castle Robert Luckay as Professor Yuri Gradenko Abram Rooney as Dr. Clifford Gibbs Daniel Attwell as Mick Mitcham James Laurenson as Professor George Amory Dawn Hope as Adelaide Smalls Ruby Thomas as Tessa Knight Natalie Grady as Ruth Hargreaves