Four people on the Seattle Underground Tour vanish without a trace. Special Agent Jessica Tyson is again called in to solve the unsolvable. She sifts through the winding tunnels under the Seattle streets and the wandering minds of the homeless above. Has the suspect created the perfect crime? He’s right under their nose, but no evidence. Jessica’s final search leads deeper into the unforgiving world of the homeless and the darkness of a bi-polar mind. While working the case, Jessica and her boyfriend, David take in Melinda, a throwaway teen, and help her find focus in life. Melinda’s experiences of living on the street lend valuable information to the investigation. Jessica apprehends the suspect and takes on a more rewarding roll for her future.