I know that the Brackett draft of ESB & subsequent drafts are completely incompatible, it's not even possible to say that the Father Vader revelation could have occurred in a later episode, had the Brackett storyline been followed. My point is that it's possible that the idea could have occurred to GL before the Brackett draft was done as a completely alternative storyline - the 1978 Future Magazine article which was written while Brackett was still writing her draft even suggests that there were two potential storylines in the air for the next SW film: Yes, Leigh Brackett was dead by the time this article was printed (she died on March 18, 1978), but I think it's fair to say that it was written while she was still alive, as it refers to her in the present tense. It could have been written months earlier, and almost definitely was. It's possible that Future Magazine's 'source' was the speculation of David Prowse, as mentioned earlier in this thread, but even then we don't know for sure what his source was, either. Point being that these strange 1977/78 spoilers that went virtually unnoticed at the time can't be easily dismissed, and do point to the idea that the Father Vader storyline existed as a concept while the 'orthodox' Father Skywalker storyline of ESB was being officially written by Leigh Brackett. I'm not saying that it definitely was the case, just that it's possible. It's getting into unfalsifiable territory, although these spoilers could be considered dubious evidence, as opposed to none. Of course not. My point is that 'Father Vader' is a character who came to be as the result of years of writing & re-writing - the evidence of which exists in these characters as pieces of a greater whole - & I don't think the massive transformation from one-dimensional villain to complex, tragic figure necessarily occurred in the neat, linear fashion zombie would have you believe, i.e. after GL simply decided Brackett's draft wasn't what he wanted, then had to come up with something completely and utterly new. I don't think he simply stopped thinking about his story after she started writing, nor do I believe that alternatives didn't occur to him while said writing was being done, or even before. However, as I pointed out in a recent post, we're really only quibbling over a period of a couple of months, I'm not trying to argue that the Darth Vader we saw in Star Wars/ANH was ever meant to be anything more than the villain he was presented as, or that Ben Kenobi's words to Luke were meant to be taken at anything other than face value.