The Giver takes place in a pseudo-Utopian society. Everybody obeys strict rules and lives together in harmony. Apologies are given for even the slightest infraction. Children are free to explore different fields and volunteer in different areas. This will be used as input to their future career. However, when they come of age, their career will be picked for them. Reproduction is also carefully regulated, with everybody on an 'urge' reducing pill and special "birth mothers" producing all the children of society. When somebody is no longer needed they are 'released' out of the community.
In order to hold this society together, a "keeper of memories" holds onto all the "strong" memories so people don't have to. Only one keeper (and possibly a trainee) can exist at time. The keeper is the one that has more extensive knowledge of how society functions and provides guidance for difficult decision making. However, the keeper is not a true leader of society. If the keeper leaves, the society may have to handle the difficult memories themselves.
The Giver centers around a new keeper and his challenges. He discovers that there are some dark parts hidden under the fascade of the community and that he will run away from it.
Plotwise, there is not a whole lot going on. However, there are plenty of big questions. How much should a society be shielded? Does it really matter that society does not have all the many memories (both good and bad)? By keeping the "big" memories away, does that merely elevate the small memories to their state? Are the people truly free? They may be lacking in many memories, but it is impossible for us to know everything. Does it matter that they know how the memories are curated? (Would it be better to have things organically curated by the media and other groups?) What are the consequences of removing the "bad apples" from the society? Will this prevent innovation? Will it lead to the eventual destruction? (Or is it the one thing that keeps the society from being destroyed.) What is freedom and who is free?
The questions could go on and on. You can see why this would be a great book to teach in school. It has a few opinions, but keeps enough ambiguity to allow just about any interpretation.
Messenger is the third and shortest book in the Giver Quartet. It follows more closely with the second book, and only superficially connects to the first and forth book. The series feels like two separate ones. Giver and Son go together, while Messenger and Gathering Blue are tied together. Had they been marketed as such, the reading experience would be much less frustrating.
The end of The Giver left many questions unanswered. You would think the sequel would fill in the blanks. Alas, in that you would be mistaken. (Try "Son", the fourth book in the series.) Instead, Gathering Blue takes us to a totally different area of the same "Giver" world. A young girl has a special gift, but also a physical abnormality. She is brought into the castle to serve with others. She learns that though she is treated well, she is also being "imprisoned" to have her talents used for the benefits of others. She eventually discovers her father and leaves. In some ways it is a repeat of the Giver, with a similar story arch in a very different community. Other than preparing us for the community of the fourth book, the second book is not critical in the Giver series.
After meandering around a few other side stories, the Giver series finally returns to the original story line in the conclusion. Son starts out in the same village as the Giver. We follow the story of a girl who became a birth mother. We gradually learn that she had lived at the same point in time as the Giver. She had a difficult birth and was then reassigned to a different job. However, in reassigning, they had forgotten to give her the "pills" that cut off emotion. She had the yearning to see her son, and eventually found him at the nurturing center. After he Jonas flees with baby Gabe, she ends up boarding a boat and ending up in another village. There she discovers a society vastly different from her own. (It somewhat resembles a somewhat primitive society with little technology, but a degree of learning and understanding.) From there, she builds up strength to climb out and find her son. Alas, she makes a great trade with the Trademaster and loses her youth in exchange for seeing him. She doesn't let him know until near the very end.
