What will Macbeth do about Banquo?

I think that Macbeth will end up killing Banquo to "silence" him leading into the sons of Banquo to want revenge. Thus leading into Macbeth dying and The sons becoming king. I only say this because if you follow the signs from not only the withches but the hidden subtext of shakespere's words you will be able to guess whats going to happen next.