▁It ▁was ▁announced ▁in ▁ 1 9 8 5 ▁that ▁Michael ▁Gra de , ▁controller ▁of ▁BBC 1 , ▁had ▁cancel led ▁a ▁number ▁of ▁long - running ▁program mes ▁in ▁order ▁to ▁help ▁fund ▁the ▁launch ▁of ▁a ▁new ▁soap ▁opera ▁named ▁East End ers . ▁Of ▁the ▁many ▁program mes ▁that ▁were ▁cancel led , ▁Doctor ▁Who ▁was ▁the ▁most ▁high - profile . ▁A ▁campaign ▁was ▁quickly ▁launched ▁by ▁the ▁national ▁press ▁to ▁see ▁about ▁its ▁return ▁and ▁Gra de ▁very ▁quickly ▁confirmed ▁that ▁Doctor ▁Who ▁would ▁be ▁returning ▁in ▁ 1 9 8 6 . ▁ ▁Several ▁stories ▁had ▁already ▁been ▁in ▁the ▁planning ▁stages ▁for ▁the ▁ 2 3 rd ▁Season ▁of ▁Doctor ▁Who , ▁three ▁of ▁which ▁were ▁in ▁the ▁middle ▁of ▁being ▁script ed ▁when ▁the ▁announ cement ▁was ▁made . ▁W riter ▁Philip ▁Martin , ▁who ▁had ▁seen ▁m ild ▁success ▁with ▁his ▁script ▁for ▁Ven ge ance ▁on ▁Var os ▁the ▁previous ▁year , ▁was ▁asked ▁by ▁producer ▁John ▁Nathan - Turn er ▁to ▁write ▁a ▁script ▁containing ▁the ▁return ▁of ▁the ▁popular ▁Sil , ▁introduced ▁in ▁that ▁story . ▁He ▁also ▁requested ▁the ▁inclusion ▁of ▁the ▁Ice ▁War riors , ▁who ▁hadn ' t ▁been ▁seen ▁in ▁Doctor ▁Who ▁since ▁The ▁Mon ster ▁of ▁Pel ad on ▁in ▁ 1 9 7 4 . ▁As ▁the ▁third ▁in ▁production , ▁this ▁script ▁was ▁the ▁least ▁complete ▁at ▁the ▁time ▁of ▁the ▁can cellation , ▁and ▁no ▁director ▁had ▁yet ▁been ▁announced ▁( ev