Spock's Brain is a workable premise and some rewriting could have saved it. Rather than remove his actual brain, his intellect could have been stolen, sealed in a portable receptacle, leaving the physical brain behind (like Star Trek III and his Katra). Then figuring out how to return his intelligence would be the issue and no real super-surgery would be required. Keep zombie Spock on the ship until necessary. Or have Kara just take his entire body (lock Spock and barrel) and then remove his intelligence on the planet. They find Spock, but the shock ending of the act is that he is mindless. Turn the women into more intelligent people who desperately needed Spock's mind to save their fragmented civilization and this may have been a real winner. None of these changes would have cost more money and might have even led to a great season opener.