Mill Creek Malice. CJ Hand Novels, #2

The animal stench triggers Dawn's gag reflex. The constant grinding of stone on stone irritably attacks her frayed nerves. The noise abruptly stops. Odd scratching sounds echo in her half-conscious state. She pulls herself into a sitting position and stares at a cage door. She gasps at the creature peering into her eyes.   Federal investigators, Tom Thies, and Dr. Trisha Baker run into problems with the odd disappearance of a professor.
Tom asks for CJ Hand's help because of his native plant knowledge. As CJ digs into the former professor's files, he discovers a unique plant variant of the hoary puccoon. On finding the plant, he launches into a geocache challenge. The clues inside the geocache boxes begin a match of wits with an intellectual killer.   Complicating the case is CJ's summer class he has contracted to teach. The new dean suggests he violates his by working the case with the federal officials.     Time is against him and his partners working the missing person case.
How does a small reptilian creature and an oddly named plant figure into the tormentor's game?