March 29th, 1975 is a day that the parents of Heather and Sunny Bethany will never forget. In WHAT THE DEAD KNOW, a normal everyday outing turns tragic when two sisters never return home from their trip to the mall. For years the parents of the Bethany girls prayed for the safe return of their daughters, but after 30 years has passed they have given up any hope. The mother, Miriam Bethany, has since divorced and moved to Mexico. The father, Dave, has passed away. The lead detective, Chet Willoughby, has since retired but still holds the unsolved case close to his heart.

A hit and run accident leads to the perpetrator being questioned by police. Instead of explaining what happened, the woman tells the police she is one of the Bethany girls. The detective is young and not familiar with the 30 year old case so the name doesn't ring a bell with him. After going to the hospital for her injuries, she refuses to tell the police anymore info about who she is. After some questioning, the girl claims to be Heather Bethany, the younger of the missing and presumed dead Bethany girls. ''Heather'' goes on to tell of her harrowing kidnapping and claims to have been held captive for numerous years, to finally be let free at 18 years old. She claims a police officer was her kidnapper.

No one believes this girl is actually Heather Bethany. The detective in charge of the case is a young man by the name of Kevin Infante. He enlists the help of retired detective Chet Willoughby to help him solve this 30 year old case. Where has Heather been for all these years? Why chose to reveal her identity now? Where is Sunny Bethany? Was a police officer really responsible for the kidnapping of the Bethany girls?

The story spans back and forth from present to past and has numerous points of view. WHAT THE DEAD KNOW seemed like a promising book, but fell flat for me. The characters were not likeable, the story jumped all over the place, the reasoning and explanation of the ending was far fetched, there was no suspense, and the writing just left me bored and uninterested. The truth isn't revealed until the last 30 pages or so, and the shock of it leaves the reader to feel lied to and fooled. There were no clues as to the ending which left me with no way of even suspecting the outcome. Overall, this was a tame mystery that did not blow me away.