Is science's understanding of how memory works quite as cut and dried as once thought? In recent years several heart transplant recipients have reported unexpected side effects including experiencing memories, habits and desires they never had before. With studies showing that these are not isolated cases, we meet patients searching to understand what has happened to them. The film follows organ recipients as they make contact with their donor families in an effort to understand their new-found lease of life, and features scientists who are pioneering research into the intelligence of the heart and the biochemical basis for memory in our cells.