Rollback
Robert J. Sawyer
 The novel focuses around Don Halifax and his wife of sixty years, Sarah, an astronomer who translated the first transmission sent from an extraterrestrial source to Earth 38 years prior to the opening of the story. Sarah, now 87, is tasked to decode the second message sent from the unknown alien race - if she can live long enough to do so. A wealthy industrial billionaire, Cody McGavin, offers to put up billions of dollars to perform a "rollback" on not only Sarah, but her husband of 60 years, Don. This process, which reverts a person's body to a much younger state, is successfully performed on Don, but fails to work with Sarah. This leaves Sarah gradually creeping toward death while Don's life begins anew. Much of the story focuses on Don as he discovers the advantages and disadvantages of being young again, with periodic flashbacks to when Sarah translated the first alien message.