When Rachel and Aidan fell in love, they thought it was forever. She was a brilliant high-flying scientist; he was her loving and supportive husband. Now she's gone, and Aidan must carry on and raise their teenage daughter Chloe alone. But Rachel has left behind her life's work, a gift of love to see them through the dark days after her death. A gift called iRachel, a humanoid robot. Not just one that can carry out tasks, but one that can also express empathy and be a companion. At first, Aidan and Chloe are convinced that having Rachel's neater, calmer twin in the house is creepy. Then they get to know her. What follows is a story about love, loss, grief and hope - and what it is to be human.