You construct a wall of blowing dirt and grit at a point you can see within range. The wall can be up to 30 feet long, 10 feet high, and 10 feet thick. The wall blocks line of sight, and a creature is blinded and deafened while within the wall. When a creature enters the wall or starts its turn there, it must make a Strength saving throw. On a failure, each foot that the creature moves through the wall costs 6 feet of movement. On a success, each foot that the creature moves through the wall only costs 3 feet of movement.   The wall disappears when the spell ends.