Insurgent

The Book

Having foiled the attempt by Jeanine Matthews and the Erudite to mind control the Dauntless to do their bidding, Tris, Tobias and a group of rebels are pursued as they move from faction to faction. The visits to Amity, Candor and the factionless give us a bigger picture and help flesh out the differences within the different groups. It also brings together characters from each faction, where familial and friendly loyalty sometimes overcomes the faction traits.
Jeanine continues to pose a threat, expanding her control to include Candor and experimenting on Tris in order to overcome the Divergent strain that is resistant to the mind control serum. 
The last 100 pages are non-stop action, whereby the factionless and Dauntless team up to storm the Erudite's fortress, which is protected by controlled Candor.
The second book in the trilogy is much more satisfying to read and provides at least some explanation for the strange divisions in the society, with a grand reveal at the end:

The Giver

Oh no, not another young adult dystopia novel! Lois Lowry's classic and popular story was written in 1993, however - way before trend. It could be seen as the young adult novel that started the ball rolling, in fact, and has so many elements that stay with you after reading.
It has all the usual requirements of the genre: strict rules and regulations, assigned roles within the community, selection ceremonies and callous leaders. It is not until Jonas on his twelfth birthday is selected to be the next Receiver of Memory that it starts to become clear just how bad things have got in this alternative society.
There are illustrations in my version by Paul Cox and they feel totally wrong for the tone of the novel. It even becomes a bit dubious, when the young Receiver has to lie shirtless on the bed and the Giver, a smiling old man, puts his hands on his back.

The Giver is a benign figure, however, who is the holder of all the current and past population's memories. He passes them on to Jonas through touch and Jonas experiences the memories for the first time - family Xmas', sledging in the snow but also war, pain and suffering. He holds these to protect the rest of the people but it is a heavy burden and The Giver's previous chosen incumbent (his daughter) committed suicide.