Helaman 5:34

And it came to pass that the Lamanites could not flee, because of the cloud of darkness which did overshadow them; yea, and also they were immovable, because of the fear which did come upon them.

The Lamanites could not run away because of the dark cloud that covered them. They also could not move because they were so afraid.

The Lamanites couldn’t run away because of the cloud of darkness covering them. They couldn’t move at all—they were frozen with fear.