 Tony <unk> , who had impressed Pattillo and the Andersons with an <unk> script that he had written for Danger Man , was recruited to assist in the writing of subplots and <unk> material . He found that the longer format created opportunities to strengthen the characterisation . Science @-@ fiction writer John Peel suggests that " small character touches " make the puppet cast of Thunderbirds " much more rounded " than those of earlier APF series . He compares the writing favourably to that of live @-@ action drama . The new footage proved useful during the development of the first series finale , " Security <unk> " : since the previous two episodes had <unk> their budgets , Pattillo devised a flashback @-@ dominated clip show containing only 17 minutes of new material to reduce costs . 
