what did they discover at the cliff

Minho is sure that something is going on at the Cliff. Three times they have seen Grievers go over the Cliff edge. It seems that this is how the Grievers leave the Maze. Thomas believes that if the Grievers can leave like this, so can the Gladers. Minho suggests they test Thomas's hypothesis first.

Minho gathers a few rocks and pebbles and the two boys begin tossing the rocks into different areas of the gray sky. All the rocks fall into the gray abyss until one of Minho's rocks disappears. Minho wonders how they missed that before, but the spot is quite small, only a few feet square.