One of the great unsolved serial killer cases in U.S. history is that of the infamous Zodiac Killer. In UNSUB, author Meg Gardiner puts forth a fictionalized account of a serial killer, who refers to himself as the Prophet, terrorizing the Bay Area in California. The question for Detective Caitlin Hendrix and her team is whether this is a copycat killer or has the Zodiac woken up after over 20 years of silence to kill again.

Caitlin has her own reasons for wanting this monster found and stopped. Her father, Mack Hendrix, was the lead detective on the Zodiac/Prophet case back in the 1990s, and he failed in every effort to stop the perpetrator. It drove him right to the brink of madness, and he has been tormented in the years following this case for his inability to protect his city.

The FBI tagged the killer as an UNSUB, an unknown subject. The only thing they do know about him is a similar M.O. he leaves behind on the seemingly unrelated targets --- an ancient sign for Mercury etched into the flesh of each victim. When two bodies turn up with these same markings, the authorities immediately spring into action. For Caitlin, it will also mean sitting down with her father and making him relive his worst memories in an effort to stop whoever is behind these latest killings.

"This chilling novel, above all else, shows us that evil does not always die. Sometimes, it is merely sleeping. Gardiner has done her part to poke at evil with a fictional stick as we sit by and watch it wake up once again."

Gardiner quotes from Nietzsche, which can serve as a warning to Caitlin: “Whoever fights monsters should see to it that in the process he does not become a monster.” The Prophet held the Bay Area in his grip for five years during the original kill spree. Caitlin wants to avoid at all costs a long and drawn-out case that threatens to put her in the same state in which her father now lives.

As the body count starts to rise, the pressure becomes almost unbearable for Caitlin. A local reporter chooses to make her, and her father, the subject of a new series of articles outlining their failures at stopping the killer. In order to figure out who might be behind these murders, it must be determined if it is indeed the original killer and, if so, what made him stop killing for all those years in between.

The police are being taunted by the killer in many ways --- through written messages, phone calls and grisly tableaus created from the bodies of his victims. One particularly eerie present is a car filled with the bodies of dozens of dead crows, and every single one of them has the head of a doll where their actual heads once were. A shrewd Caitlin begins to work on deciphering what they know. She recognizes that Mercury could mean many things, one of which was the guide of souls in the underworld.

When Caitlin figures out that the Prophet’s messages somehow play into the text of Dante's INFERNO, she gets a glimpse of his ultimate goal. The Prophet is revealing each layer of hell to the world. The problem is stopping him before he gets to the center of hell itself whereby he is probably saving his ultimate reveal to the world. The Bay Area is again held spellbound and wracked with fear. Readers will find themselves just as awestruck with apprehension with each turning page as to what UNSUB will hit you with next.

If you enjoy Meg Gardiner's work as I do, then we probably all have Stephen King to thank. It was his praise for her novels that really put her on the map domestically. Even though she is a U.S.-based author, she first found success overseas in the U.K. with her terrific Evan Delaney series. In the case of UNSUB, she has trolled the annals of true crime by awakening the evil spirit that haunted the Pacific Coast later named by authorities as the Zodiac Killer. This chilling novel, above all else, shows us that evil does not always die. Sometimes, it is merely sleeping. Gardiner has done her part to poke at evil with a fictional stick as we sit by and watch it wake up once again.