This is not quite a novel, but not quite a short story collection either. It consists of five stories taking place in different times, but bound together by recurring characters.
The first (and longest) part "Low Men in Yellow Coats" takes place in 1960. Bobby Garfield has just turned eleven, but his mother can't afford to buy him the bike he wants. She keeps repeating that they are low on money since his father died.
As usual when King writes about children it is very well done. There is a sense of being in the middle of Bobby's last summer as a child and the first as almost grownup. Bobby decides to try to earn the money for the bike himself. As the same time he realized that his friend Carol Gerber isn't just a friend, but that he's in fact in love.
To get more money, Bobby's mother rents out a free room in their house to Ted Brautigan. It is obvious that she doesn't like Ted, but Bobby does. Ted spends a lot of time discussing books with Bobby (who has just gotten an adult library card for his birthday) and gives him Lord of the Flies that makes a huge impression on him.
Ted proves to be a bit weird. He claims to be hunted by low men in yellow coats. He doesn't want to say too much about them, but he asks Bobby to keep an eye out for them and let him know when they are near. Bobby gets paid for it, but doesn't take it seriously and fails his job. These mystical men are really the only supernatural element in the book, the later parts are entirely realistical.
The next part, "Hearts in Atlantis", takes place in 1966 and is about Peter Riley who has just started at the university. He has been a good student before, but now he's drawn to the interminable card games in the communal room in the dorm where he lives. He does succeed not to lose money, but his studies quickly fall behind. Failing is not a nice option either, since that will almost certainly get him drafted and flown to Vietnam.
His situation doesn't get any less complicated by meeting Carol Gerber and falling in love with her, in spite of the fact that both he and she have previous engagements at home.
To begin with, no one knows what the symbol on the back of one student's jacket means, but pretty soon the peace sign has spread to almost everyone. More and more people are starting to question what the US are really doing in Vietnam. Carol is drawn to an activist group and is soon taking part in bloody demonstrations.
The last three parts are shorter. One is about a Vietnam veteran's penance after the war, one describes a reunion of two vets on the funeral of a third, and in the third Bobby returns to his home town after almost forty years.
The plot in the different parts isn't connected, but they still feel connected since there is always at least one previously familiar person in each story. A supporting character in one story may be the protagonist of the next. Towards the end of the book one has a more complete picture of the lives of the different characters and what has made them the persons they became.
It is obvious that these are time periods and environments that Stephen King is well acquainted with. The descriptions of places and people are excellent all the way. Even if the theme isn't what one is used to in a King novel, he is still recognizable through his style.