From - Season 4 Official Teaser Trailer

In Season Four, the closer the residents of town get to the answers they seek, the more terrifying their search becomes. Who is the Man in Yellow, and what does he want? Will Jade and Tabitha’s revelation be the key to finally going home? How much longer can Boyd hold the town together, even as his body and mind are falling apart? And what role will the town’s most recent arrival play in the events to come? Season Four will open doors that some in town will end up wishing had remained closed.