Each investigator has that one case that haunts them, the one that just won’t budge. For Detective Tim Horne, the Billboard Boy was that case. He was just a young crime scene tech when the skeletal remains of a little boy were found beneath a billboard in his jurisdiction. With no leads, the unsolved murder turned into a cold case. But Horne kept the case in a box beneath his desk where he would literally bump into it for the next 25 years. It was a daily reminder that he needed to solve it. The unidentified remains couldn’t stay unidentified forever. 
When the clock starts ticking down to his retirement, he knows it’s now or never. Horne is determined to make something happen. 
That’s when he turns to forensic genealogy, and the research of Barbara Rae-Venter. Famous for her work on the Golden State Killer and Bear Brook cases, Rae-Venter uses DNA profiling to provide a single piece of information that could help Horne solve the case. But can he do it before time runs out?