The average human being lives from 0-80 sequentially. Spanners don't. These rare beings have different lifespans than the rest of us. Some live their lives in reverse, some live only six months, and some are immortal. There are hundreds of classes of spanners that live hundreds of different ways, and each class has a unique lifespan that gives them unique powers. Dr. Adam Parr is an immortal, the highest class of Spanner. When Dr. Parr finds that his immortal brother Jonathan has somehow been murdered, he must reconnect with his detective roots to solve the crime. Dr. Parr teams up with a short-living, fast-learning Mayfly and delves into the Spanner underworld - because if someone could kill his immortal brother, Adam might be next.