Herman: is the only move to start with. Allowing white to play here would allow some of his stones to live. With , white captures 18 stones. Then...
removes any eyes along the edge, by making the a marked points miai. is a threat to capture , and also to make eyes is the center
With , the marked stones are captured, and there are no eyes along the edge. afer , white is dead, as black captures at least one of the marked stones. Switching and does not work either, as white will then have only one eye.
unkx80: This killing sequence is exactly what I have in mind. =)