When a near death experience has Mac Taylor contemplating whether it's time to end his career, he becomes determined to close his last remaining unsolved case so that he can be at peace with his ultimate decision. Mac originally thinks the nine year old unsolved case relates to a convenience store robbery gone wrong. Hawkes re-examines the DNA evidence at the scene and finds that a young girl, who was reported missing the night of the robbery/murder, actually witnessed the murders in the convenience store that night then was kidnapped by the two suspects. Mac searches for the girl and the team catch a break after they publish a postcard an ex-girlfriend of one of the suspects gave them with the suspects distinctive handwriting. They discover the girl is still alive and one of the suspects is raising her as his own. Mac and the team track them down but the suspect isn't giving her up easily. After closing the book on his last unsolved case, Mac contemplates the idea that maybe he has done all he can here at the CSI Crime lab.