 The finale contains nineteen principal cast members , sixteen of whom appear in " The Stolen Earth " . As a consequence of the episode 's crossover nature , the episode is the first appearance of Gareth David @-@ Lloyd as Ianto Jones and Tommy Knight as Luke Smith in Doctor Who . Eve Myles , who previously played Gwyneth in " The Unquiet Dead " , makes her first appearance as the Torchwood female lead Gwen Cooper . The episode features many returning characters : Billie Piper , Freema Agyeman , Adjoa Andoh , John Barrowman , Nicholas Briggs , Elisabeth Sladen , and Penelope Wilton reprise roles for " The Stolen Earth " . Evolutionary biologist Richard Dawkins and comedian Paul O 'Grady make cameo appearances on Torchwood 's television screen ; cameos by celebrities such as Davina McCall , Derek Acorah , and Ann Widdecombe had been a part of each penultimate episode since the show 's revival . O 'Grady was given a cameo after Davies heard that he was a fan of the show ; and Dawkins was added to the script by Davies when Cook suggested him to portray the " elderly professor " on a Newsnight @-@ style television programme discussing the new planets in the sky . Dawkins accepted because of his pre @-@ existing association with Doctor Who ; his wife Lalla Ward portrayed the second incarnation of the Time Lady Romana between 1979 and 1981 . Gary Milner was cast as the extra " Scared Man " after misreading the callsheet as " Sacred Man " and creating a " priest @-@ like " portrayal of the character . Andrew Bullivant — who portrayed the Milkman in the episode 's cold open — was given a role in The Sarah Jane Adventures serial The Temptation of Sarah Jane Smith as a policeman because of his performance in " The Stolen Earth " . Michael Brandon later appeared in the audio play Lurkers at Sunlight 's Edge . Kelly Hunter made a further appearance as the Shadow Architect in the opening episode of Series 9 , " The Magician 's Apprentice " . 
