What are the Borg? What is knowledge? What does it even mean to "know" something?
These are just a few of the questions explored in this episode which is primarily focused on the Borg and the Federation - two vastly different organizations that explore the universe very differently and with very different intentions. Why? And how does that reflect our understanding of things we believe we "know"?
There are spoilers, primarily referencing Next Generation and Voyager.