LAPD detective Michael Gideon and his German shepherd K-9 partner, Sirius, walked through fire to catch an infamous serial killer, and Gideon is still paying the price with his PTSD fire dreams. To assist the FBI's Behavioral Analysis Unit, Gideon has agreed to monthly prison visits with Ellis Haines, aka the Weatherman. This time, a homicide case the FBI wants Haines to analyze sparks a chilling discovery: A new serial killer has struck, and he's lacing his crime scenes with hidden messages intended for Haines. Haines isn't the only killer whose twisted game Gideon must try to break up. A missing man's love poems are delivered to his fiancée with the message: And when a sweet pit bull named Emily is rescued after being left for dead, Gideon and Sirius pull out all the stops to try and bring down the dogfighting ring that abused her.