Let Sleeping Princesses Lie

She woke up with the vile smell of troll strong in her nostrils. She grabbed the dagger under her pillow.
         There was a prince standing over her, reaching out to help her to her feet. She could hear the castle's inhabitants stirring. The cursed sleeping spell was broken!
         "You're awake!" exclaimed her saviour.
         The princess's father had been a monster hunter in his youth, and he taught her how to recognise a true monster. She could see this individual was half a troll and probably a child eater.
         "Yes. I'm awake," she agreed, and then stabbed him though the heart.