When my drink is ready ...

I love that line and the way it can affect an audience, filling them with admiration and dread for the forthcoming act, so colorfully, and so crudely described as a drink. But I also think it is the key to that dagger speech which directly proceeds the act. The act of Duncan's murder is the main locus of event in the scene, towards which all the life points, but this line creates a hollow space just before it. As such, after parting with Banquo and then dismissing the servants there is this odd, almost absurd moment when there is nothing to be done, nothing at all but wait for the ring of the bell. After all he has settled upon performance of the terrible feat and this then is not so much a moment of comtemplation. But still he must wait before he can perform. Its wonderful, and mundane, and human, that this exists in the play. Its like the the Dumb Waiter, where the murderers must wait for the call, and the waiting time, where nature goes way to dangerous thoughts in repose, is here illustrated. I think in the course of the speech he forgets the very thing that he is waiting for, and has almost forgetten it completely, until the last beat when in frustration he mocks the speech itself - words to the heat of deeds, too cold breath gives. I think at this point he is anxious to get the thing started, and then in direct response to that anxiety, his call is answered by the bell that invites him to his terrible drink.