Instruct: Classify a given review into positive or negative sentiment.
Query: Darker in content than previous seasons

We've watched the previous three seasons of THE DEAD ZONE in quick succession, and generally enjoyed every episode. The fourth season is darker in content with more standalone episodes. The Stillson and Purdy backstory is only seen now and then. "Heroes and Demons" is probably the best episode from season 4. Still good viewing but we no longer feel compelled to watch without a break, as we did while watching seasons 1 and 2.