And these two electrons that were in the sigma bond now nucleophilically attack the carbon and this displays the pi bond in the same way that we displace the pi bond here. And in the same way that we form this tetrahedral intermediate, we also form a tetrahedral intermediate in step five. And once again, to stabilize that relatively unstable and negatively charged tetrahedral intermediate, we have this oxyanion hole that contains the partially positive charge H atoms that can stabilize this full negative charge. And so, because it's so unstable, it doesn't exist for a very long time. And what happens is, again, the two electrons on the oxygen basically form a pi bond between the carbon and this oxygen. And now what happens is this bond here showed in green that we basically formed in this step is now broken.