Thayne Wolfe and Jarrett Evans have been working together for nearly a year. Now, living together as well, their relationship has taken on a whole new meaning for both men. It seems that danger has always been a part of their lives in the ATF but when SAC Stanger sends them to a relatively routine crime scene, things quickly get complicated. Someone has been arming Los Angeles street gangs with automatic weapons missing their serial numbers. Lincoln Snow from the FBI's LA field office, has a new partner, McBride M. McCallahan, a massive former Green Beret. The men are chasing a kidnapper, trying to rescue a child from an online sex ring. When their case intersects with the ATF's through stolen weapons, Lincoln and Mac team up with Jarrett and Thayne to solve their case as well. From a desert hunting lodge for the insanely wealthy, to the gang-infested streets of Los Angeles, the men follow the guns to solve both their cases. In a race for time to save a little boy and keep themselves above ground long enough to find out who's pulling the strings, all they want to do is put this case to bed.