 In the mid @-@ 1970s , Kneale made his only attempt at writing a stage play . Called Crow , it was based upon the memoirs of real @-@ life Manx slaver Captain Hugh Crow . Kneale was unable to find backing to produce the play for the stage , but sold the script to ATV who put it into pre @-@ production for television . However , shortly before filming it was cancelled by order of ATV 's managing director , Lew Grade — Kneale was never told why . 
