America has five branches of the military... Sixteen different intelligence agencies... A thousand elite police forces... And one woman keeps them all in line! HEARTBURN While investigating the disappearance of an US Marine recruit at a top secret SERE (Survival, Evasion, Resistance & Escape) training site, AVRIL HEART, an undercover Department of Homeland Security agent, endures 'enhanced interrogation' in order to learn the truth. After the death of another Marine cooperating with her investigation, Agent Heart discovers a shocking conspiracy that calls into question everything she is fighting for.