Stephanie Doyle 
Calculated Risk [EPUB ebook] 

At the ripe old age of twenty, girl genius Sabrina Masters was booted from the CIA for "willful insubordination." Now, ten years later, they want her back for a mission only she has the brains to complete-breaking a twisted code to flush out a terrorist. Too bad the mission comes with her former trainer and ex-lover-Quinlan-attached.With national security at risk, Sabrina doesn’t have time for rules or distractions. Especially from Quinlan. A decade out of the spy game means the odds are against her-but they don’t call her a genius for nothing….