We left episode #720 with the man stalking Mac, Raymond Harris, arming himself with a large cache of weapons. We open this episode on a normal day at the crime lab with Mac sitting at his desk when Hunt (played by Peter Fonda) enters, claiming he received a text from Mac to meet him in the lab. Mac claims he never sent a text then suddenly the glass windows behind Mac's office shatter in a hail of bullets being fired at him and Hunt from a vacant floor in the building across from the lab. The shooter flees but our CSI team find trace evidence in a duffel bag and weapon left behind. The evidence leads Mac and Hunt to the apartment where they arrested Harris on drug charges 17 years ago. When Mac and the team storm the apartment they end up in a shootout and kill the occupant of the apartment; but the man wasn’t Harris. Utilizing spatter science, Mac discovers the truth behind Harris' rage - Hunt. Hunt stole money from Harris the night he was busted. We soon find out Harris' girlfriend was also murdered while he was in prison by Hunt. We race to a standoff between Mac, Hunt and Harris where someone doesn't survive.