I enjoyed this for the most part! Good read. If I had any criticism for the King, which I'm always hesitant to criticize the most appropriately named author, it would be the dialogue at times. Seems a bit too professional, almost like what you would expect robots to say. Another thing that bugged me was switching the 3rd person multi narrative from person-to-person so quickly with the short chapters.
The climax of the book was intense, and had my heart thumping and utterly hyperfocused on the pages as I read to see what was going to happen to our heroes Luke, Tim, and all of the Institute's prisoners. It had a satisfying end to the story despite the foreshadowing of a more sinister outcome ie "living in a world where the good guys don't always win."
It had a great storyline and I found Luke's POV to be the most engaging and well done. King really develops the protagonist to where we feel his pain, feel his hopelessness, his dread, his uncertainty, his pain, but also his resolve to save his friends, learn all that he can, and put an end to the tortuous agenda of The Institute.