I have no idea if this is true IMDb is unreliable. Here is the link for the descriptions http://www.imdb.com/title/tt1520211/episodes?season=4&ref_=tt_eps_sn_4
As the survivors of the prison assault try to regroup, Rick and Carl stumble upon a vacant house in the forest. Meanwhile, Daryl and Beth realize they are being watched by someone, and a new threat begins to emerge. This episode is mostly just going to be about Rick and Carl, Beth and Daryl are probably just in for a couple scenes and the hunters will be introduced.
The scattered groups begin to reunite, but it becomes apparent that the mysterious killer may still be at large. This most likely is the episode when the hunters kill someone in the group and the groups reunite. I have terrible grammer so i'm sorry if some of it does not make sense.