The series ran semi-regularly from 1997 to 2004, broadcasting for four series and two Christmas specials, initially co-starring Caroline Quentin as Creek's collaborator, writer Maddy Magellan. After Quentin's departure in 2001, Julia Sawalha joined the cast as new character Carla Borrego, a theatrical agent turned television presenter. Following a five-year hiatus, the series returned for a one-off special on 1 January 2009, "The Grinning Man", which featured Sheridan Smith as another paranormal investigator with whom Creek joins forces. A further 90-minute special "The Judas Tree", was filmed in October 2009 and broadcast on 4 April 2010; while a third special, "The Clue of the Savant's Thumb", was shown at Easter 2013. Smith had previously worked with Renwick on his sitcom "Love Soup".