In full view the rope is sliced into two parts. The cutting machine is returned to it's normal position and the rope is removed, completely restored. This one is clean and easy to do. The hand justs makes a pass over the rope and it instantly changes color. A great trick you will use often.
Magician places the knot back on the rope and it magically blends back in.
Not for beginners. A length of a white rope with a knot tied in its center is used to do incredible magic. Slide the knot to the right end of the rope and then all the way to the left. A self contained miracle. Completely mechanical and impossible to detect.