 Before recording for the second season was due to commence,  David Holliday (I) (qv), the original voice of Virgil, had  relocated to the United States, so Jeremy Wilkin (qv) replaced  Holliday as the voice of Virgil for the second season and the two  Thunderbirds movies _Thunderbirds Are GO (1966)_ (qv) and  _Thunderbird 6 (1968)_ (qv).