Hammer contacted the BBC on 24 August 1953, two days after the transmission of the final episode, to inquire about the film rights. Nigel Kneale also saw the potential for a film adaptation and, at his urging, the BBC touted the scripts around a number of producers, including the Boulting Brothers and Frank Launder and Sidney Gilliat. Kneale met with Sidney Gilliat to discuss the scripts but Gilliat was reluctant to buy the rights as he felt any film adaptation would inevitably receive an ‘X’ Certificate from the British Board of Film Censors (BBFC), restricting admission to persons over the age of sixteen. Hammer was not so reticent, deciding from the outset that they would deliberately pursue an ‘X’ Certificate. Hammer's offer met some resistance within the BBC, with one executive expressing reservations that The Quatermass Experiment was not suitable material for the company, but the rights were nevertheless sold for an advance of £500. Nigel Kneale was a BBC employee at the time, which meant that his scripts were owned entirely by the BBC. He received no extra payment for the sale of the film rights. This became a matter of some resentment on Kneale's part, and when his BBC contract came up for renewal he demanded and secured control over any future film rights for his work. Despite this, Kneale remained bitter over the affair until the BBC made an ex-gratia payment of £3,000 to him in 1967, in recognition of his creation of Quatermass. The film was co-produced by Robert L. Lippert, an American film producer and distributor. Hammer had entered into an arrangement with Lippert in 1951 under which Lippert provided finance and supplied American stars for Hammer's films and distributed them in the United States. In return Hammer's distribution arm, Exclusive Films, distributed Lippert's films in the United Kingdom. Quota laws in the UK meant that US films had to have a British supporting feature, so it was in the American studios' interests to fund these features to recover a greater proportion of the box office receipts. Writing The first draft of the screenplay was written by Richard Landau, an American who had worked on six previous Hammer productions, including Spaceways (1953), one of the company's first forays into science fiction. Landau made significant changes in condensing the action to less than half the length of the original teleplay. The opening thirty minutes of the