Poison — Bridget Zinn

Sixteen-year-old Kyra, a highly skilled potions master, is the only one who knows that her kingdom is on the verge of destruction -- which means she is the only one who can save it. With no other choice, Kyra decides to do what she does best: poison the kingdom's future ruler, who also happens to be her best friend.

But, for the first time ever, her poisoned dart . . . misses.

Now a fugitive instead of a hero, Kyra is caught in a game of hide-and-seek with the King's Army and her potioner ex-boyfriend, Hal. At least she's not alone. She's armed with her vital potions, a too-cute piglet, and Fred, the charming adventurer she can't stop thinking about. Kyra is determined to get herself a second chance (at murder), but will she be able to find and defeat the princess before Hal and the army find her: