In order to protect his family from the attentions of a crooked and violent bookmaker he is reluctantly drawn back to his old profession. During the novel the possibility of a hand transplant is mooted and the book ends with Halley being told that donor hand has become available.
In order to shield his family from a corrupt and violent gambler, he is forced to return to his old line of work.  The book explores the idea of a hand transplant as a potential solution, ultimately leading to Halley being informed that a suitable donor hand has been found.