First Contact was the last thing they expected. All the centuries of searches for extra-terrestrial intelligence turned up exactly nothing at all. But then, humanity's first colony in another star system discovered some very alarming signs that the first settlers weren't quite so alone as they thought.
What is the difference between an invader and an explorer? What if the fate of the Earth depending on a small handful of ordinary people getting the answer right? And what if they they couldn't do that until they first figured out that was the right question to ask?