Watched the first season and felt it gave a lot of promise. On one hand, the show uses the same formukla for the core of each episode, like a lot of American shows do. However it also has a complex bigger picture that, so far, it has chipped away at in each episode.
Alcatraz prison was closed down and all the prisoners transferred off the island in the 60s but the premise is that this actually never happened, that nobody seems to know what happened to them and that in the present day these prisoners begin to start reappearing with no idea what happened to them.
Where they with it will decide for me whether I like the premise or not, I think. At the moment I'm enjoying it. I just wish it had been renewed for a second season already. I hate the wait with American shows. It deserves a second season.