Unbelievable by Sara Shepard
Five best friends -- Aria, Spencer, Hanna, Emily and Alison -- live the perfect life in the perfect town of Rosewood. But behind the white picket fences and luxury cars, there's a darkness hovering over the girls. In 7th grade, Alison disappeared, and the girls went their separate ways. They put the past behind them and move on, until a mysterious "A" appears in town and strange things start happening to the girls. Can the girls figure out who killed Alison before it's too late? Will Rosewood ever be the safe-haven they once lived in? Read the fourth book of the Pretty Little Liars series to find out.

Haven't read the other Pretty Little Liars books? No worries -- we're throwing the whole series in the giveaway!

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