I didn't want to watch this season at first because season 4 of Prison break was terrible which did not give me hope for this. Seasons 2 and especially 1 were brilliant, but the show went downhill fast after that due to a writers strike. I didn't even watch the last episodes of season 4. Season 5 surprised me, that it was actually good. Especially the first half of the season that was packed with tension and action as they had to escape a prison in a warzone. This season had hints of the original and some of the second season but it dragged at times during the second half. I recommend watching it, the whole thing. I was horrified to learn that they are making a 6th season after this season wrapped up so nicely. Where can they go from here? I'm sure it won't be anywhere good and will probably be unwatchable like season 4.
