The books that inspired the SyFy series Hunters...
A young wife disappears in the night, never to be seen again. There is no evidence of kidnapping - in fact, everything indicates that she left on purpose. Her husband, a brilliant police detective, cannot believe this - but he also can't find her.
Flynn Carroll’s lost love becomes his obsession. He begins amassing a file of similar cases nationwide. His conclusion is unavoidable: somebody is taking people and making it look like they walked out on their own. As Flynn’s case files grow, his work comes to the attention of Special Agent Diana Glass, a member of the most secret police unit on the planet. This police force seeks the most brilliant and lethal criminals who have ever walked free - thieves and murderers from another world.
Without fully understanding what Glass and her team are doing, Flynn steps into a hidden world of extraordinary challenge and lethal danger. The job is the most difficult police assignment ever known to man, but the idea is the same - find the bad guys. Stop them.