If Thunderbird 2 launches from an island in the pacific and it doesn't have sound effects, does it make a sound? Of course not... In this Thunderbirds Unseen update we begin an investigation into some previous lost audio tapes from the AP Films and Century 21 studios. Will they reveal previously unheard material or help us to tell the story of Gerry and Sylvia Anderson's cult creation? There's only one way to find out...