 The series ' title sequence , <unk> by Gerry Anderson , is made up of two parts . It opens with a countdown of " 5 , 4 , 3 , 2 , 1 : Thunderbirds Are Go ! " , provided by Dyneley in character as Jeff Tracy . In a departure from the style of Stingray , the Thunderbirds title sequence varies with each episode : the first part consists of an action montage that serves as a preview of the plot . Simon Archer and Marcus <unk> , biographers of Gerry Anderson , compare this device favourably to a film trailer . 
