In ancient times Trolls lived under bridges and charged gold for anyone who wanted to cross over. Now, if you lived in modern Chicago where all the bridges are free, no one worried about the ugly little guys, right? Yet here was the investigation team, looking in tunnels for short people, all because of a hole in the ground.

Sandy just wanted to look at the sinkhole. No one had heard of a sinkhole anywhere except Florida, but here was one in a nice neighborhood on the outskirts of Chicago.
Looking at the hole means that the team of a lawyer and vampire will once again come to the rescue of their partner as she falls into the dangerous hands of a Troll King who wants gold and power and the pretty partner who slides down underground into tunnels filled with giant moles, ferrets, groundhogs and whatever else desires to live below the surface.