The Taste of Treachery by Emily Bybee

Harper is a brilliant hacker who is trying to walk the straight and narrow as a computer science major and artist. She never saw herself as an environmental activist or conspiracy theory nut. But when her brother who is serving overseas in Delta Force disappears, the last email from him pulls her into a world of secrets, mercenaries, and guns. Guns aimed at her. No one wants to listen to the ravings of a college student, much less one with a mental health history of severe anxiety. Caleb, her older brother’s best friend and fellow Delta Force operator, home recovering from spinal surgery, is her only ally. Together they work to unravel the truth behind a government conspiracy and a chemical company willing to poison the world for profit. She must put aside the growing passion between her and Caleb to stop the evil plot before the mercenaries sent to kill them complete their mission.