Spies in Saddles [Book One]

Nat has always joked about one of her best friends, Molly, being a top-secret CIA agent. After all, it always fit in with her many absences from school, distant trips on the weekends, and unexplained injuries. But Nat never considered the truth behind those jokes, because how could someone from an all-girl, Catholic school that wore saddle shoes possibly do any wrong?
And then one day in algebra-two, when a gun is shoved in her face, everything she thought she knew about Molly flies out the window. With the help of her other best friend Kate and, of course, several attractive males, Nat finds herself caught up in a plot of kidnappings, gunshots, and high-scale adventure, all taking place right inside what she had thought was her comfort zone.
Spies in saddles? Who'd have thought!