Pagoda Box Mystery

Two pieces of thin rope are threaded through solid block, then put into the Cabinet.
The rope is threaded through a hole on both sides of the Cabinet and the lid is closed to secure the Die.
One piece of rope from each side is wrapped over the lid and tied in a knot.
If you desire a spectator's hand is put below the knot on the lid.
Open the front doors, the Die and rope are securely tied in the cabinet.
You give the rope a tug, the rope ESCAPES from the Die and Cabinet!