Fog

It was still a little dark when Evie and her six vampire companions broke up camp and erased the marks of them being in the area. Once all traces of them setting up camp were removed, they embarked on their journey once again, moving efficiently and silently.

Once they reached another area, they ended up having to walk because the forest they had just entered was pretty dense. The undergrowth did not allow the vampires to run fast. It was also impossible for them to leap and travel above the tree line because of the thick blanket of poisonous fog covering the top of the forest.

The forest they had entered looked as though as it was always stuck in twilight even though it was still early morning. Evie guessed that the thick fog covering the tops of the trees was the reason that it was this way. The light could not fully penetrate the fog thus, giving it that twilight look constantly.