Guest Stars Lachlan Murdoch as Constable Henry Higgins Arwen Humphreys as Margaret Brackenreid Jonathan Watton as Dr. Darcy Garland Nigel Bennett as Chief Constable Percival Giles Paul Amos as Dr. Roberts Benjamin Clost as Teddy Nelson Ellen Dubin as Mrs. Haversham Joe Cobden as Gideon Turner Andrew Gillies as Robert Denman Nicholas Bode as William Murdoch Jr. Frank Chiesurin as Seth Morgan Colin Buchanan as Professor Harms Emily Hurson as Bystander Billy Oliver as Santa Claus