Darash Chai - Seek Life!

Numbers 5 contains a ceremony that has caused no end of confusion and consternation for quite a long time. A ceremony that not only seems barbaric to a degree, but also seems completely out of place in the text. Why now, or all places, does the text move to describe the water trial for the woman suspected of adultery? What is the context that this trial is speaking into, and what does it demonstrate about God?