I agree with strolen. The possibilities are endless. You can make it sort of like Myst, and have it focus on puzzles to get the book, or a quest bent on finding who is responsible for all the demons roaming the island. Go to Comment
A group of adventurers come across a child’s body on their adventures, odd being such a remote location. Their is no detectable sign of violence to the child, nor are their any signs of life. Suddenly the child opens its eyes, looks towards the group and introduces themselves to the adventures.
If this wasn’t odd enough, the child can’t remember where they are from, only their name and age. Stranger yet, the child has a tattoo on their right shoulder of a family crest, to a family that died out over 200 years ago.