As a veterinarian, Helena had mercifully escorted thousands of animals to the other side. Now, having died herself, she finds that it is not so easy to move on. She is terrified that her 37 years of life were meaningless, error-ridden, and forgettable. So Helena haunts-- and is haunted by-- the life she left behind. Meanwhile, David, her shattered attorney husband, struggles with grief and the demands of caring for her houseful of damaged and beloved animals. But it is her absence from her last project, Cindy-- a chimpanzee who may unlock the mystery of communication and consciousness-- that will have the greatest impact on all of them. When Cindy is scheduled for a research experiment that will undoubtedly take her life, David must call upon everything he has learned from Helena to save her. In the explosive courtroom drama that follows, all the threads of Helena's life entwine and tear as Helena and David confront their mistakes, grief, and loss, and discover the only way to save Cindy is to understand what it really means to be human.