From the PB Puzzles website:

The Quest for the Holy Grail Puzzle Box combines a sequential discovery puzzle box with escape room style puzzles in a quest to help the central character discover the Holy Grail and escape the realm with his prize.

This highly complex puzzle box hides its secrets in the pages of an ancient book, which is itself locked and bound within a cage.

You must first discover the secret to release the ancient tome from its locked cage. Upon releasing and unlocking the book itself, you must decipher the route to take; many interesting and changing routes present themselves, through which you must guide the knight on his quest to discover the Holy Grail and escape the kingdom. On the way there are obstacles, puzzles and challenges to overcome in order to progress.

To succeed in this ultimate quest you must master a journey of logic, discovery, and trial and error as you move through the sequential process to unlock the puzzle.