Like most of McCullers stories, this is concerns lonely people living in the deep south. This one is set during WW2, told with strong musical currents (she had a place to study piano at the Julliard, and this shines through most of her work) and a radical passion against poverty and injustice.
The language is generally quite simple in terms of vocabulary and sentence length, yet the characters and events are all the more poetic and vivid for this apparent simplicity - a difficult literary trick to pull off.
The main character is John Singer, a deaf mute. Biff Brannon (café owner), Jake Kelly (migrant mechanic and social activist), Dr Copeland (black doctor and communist) and Mick Kelly (girl of 13-14) all attach themselves to Singer, who is of course, the perfect listener for their varied troubles and a blank canvas for them to create him as a god-like figure of whatever kind they each want. The main plot is Singer's relationships with the other four (they have almost none with each other). The subplot is a coming of age strand regarding Mick: moving from passionate and ambitious tomboy to frustrated young woman.
Each character who unburdens themselves to Singer thinks they know him and that he is something of a free spirit. None of them know that he is pining for the burden of caring for Antonapoulos, his former flat mate and fellow deaf mute, now in an asylum. In that relationship, Singer did all the talking and assumed that wisdom and empathy came from Antonapoulos, who largely listened. Now on his own, the tables are turned and he is cast in the role of wise listener. Singer's animated hands are redundant for communication - neglected and stuffed in his pockets.
All the closest relationships in this story, even amongst the minor characters, are compromised by literal or emotional distance or largely unreciprocated, though the characters themselves are not always aware of this.
As well as sadness, there is often an underlying sense of menace, though when bad things happen, they are often not what you had expected until a page or two before they happened, making them somehow more shocking.
Overall, a powerful and sad book, yet somehow not a depressing one. Despite much tragedy, there is still hope.
NB "The Mortgaged Heart" (http://www.goodreads.com/review/show/51575682) includes an author’s outline of this book, which sheds extra light on the story, though some of her preliminary ideas were not in the final book.