Ohyes. Definitely a good one to end the season with. It wasn't as "OMIGOD, what happened/is going to happen/is about to happen and is dangerous/weird?" as other finales (see ER's "who got on the bus that exploded" trick), which often get annoying because they're so unresolved, but this left enough questions and issues around just hiding there in the background that you can keep thinking about it for a while.