Guest Stars Richard Briers as Chief Caretaker Judy Cornwell as Maddy Howard Cooke as Pex Julie Brennon as Fire Escape Catherine Cusack as Blue Kang Leader Clive Merrison as Deputy Chief Cartaker Brenda Bruce as Tilda Elizabeth Spriggs as Tabby William Perrie, John Asquith as Caretaker Simon Coady voices Video Commentator Richard Briers voices Great Architect