Caraval by Stephanie Garber

Scarlett has been writing to Legend every year for the past 7 years, but this year, she finally got the letter right. Legend is the master of Caraval, a magical, mysterious game where the winner's get fame, glory, and, this time, a wish. Scarlett and her sister Tella have been invited to Caraval, but Scarlett is about to marry a Count and finally take her sister away from their tiny island and their abusive father. If she leaves to play the game, she could ruin everything.

Caraval is a world where anything can happen and where you cannot trust anything, not even what is right in front of you. You could find yourself in a fortune teller's tent, or be asked to pay for a new dress with two days of your life, or discover that your biggest fear is the most valuable currency you posses. Scarlett is out of her depth and, after her sister is kidnapped as part of the game, without her most trusted ally. Now she has to decide whether or not to trust the handsome, roguish sailor who has become her partner in the game. She also has to find a strength within herself, rescue her sister, and get back to her home before the clock runs out on her future.

Pick this one up if you want a fast paced, mysterious, romantic adventure that will leave you saying, "So when does book 2 come out?"