Hijack = Hiccup (from the movie How to train your Dragon) + Jack Frost (from the movie Rise of the Guardians). I highly recommend you to watch both movies if you haven't done it yet before you read. The year is 2016, and new trouble is coming up for the guardians. The man in the moon decides that this is serious stuff and that they need help, so he decides a new guardian. The problem is big, bigger than ever before, but Jack's memories and relationship is only making it harder for him with the new guardian, and the old thoughts get pressed away by the new ones. I will say it now = THERE WILL BE RATED R SCENES.
3 parts