The Monolith Murders

Fred Harris, a lieutenant in the Sarasota Police Department, possesses a tiny electronic unit that had been developed for the CIA. It was removed years earlier from the brain of Donna Lang, a mass murderer, after her capture and subsequent prison sentence. But Donna Lang escapes prison and sets out to regain possession of the device. Fred Harris realizes that the reinsertion of the unit into his adversary's brain would bring havoc to his small retirement community.