If you played Riven you probably remember the daggars that appeared in the game. One of those daggars also appears in Myst IV. It's in the Cyan Worlds movie during the intro to the game. Start up Myst IV. The Cyan Worlds movie is the first thing that appears. The round "viewport" shows a fly-over of trees and houses. Keep your eye on the left side of the viewport and you'll see the daggar sticking in the ground just before the large pointed mountain.