What could be more Halloween themed than investigating a haunted house? Meg starts out looking into a missing accounting book but that soon becomes a missing person.
At the same time, back in Whisper, Rain is working on the festival, which no one wants, including her. She's approached to provide security to a farmer's property and on his way home, he's run off the road and lands in the hospital.
Clues abound but none of them point in a particular direction. When Rain, too, is run off the road, the investigators at Barringer and Associates realize they have to figure out these mysteries before someone gets killed.
Only Human is the latest installment in the Whisper series which began with Whisper Bound.