Under The Bridge

Cassie Christine Javala looked over her shoulder, laughing and running with her sister, Trista Skye Javala, away from their brother, Titus Jordan Javala. They were triplets.
Cassie and Trista kept running, then spotted a bridge.
"Hey! Let's hide under there. He won't find us." Cassie whispered to Trista. They ran over the the bridge, but when they were out of view from others, they were suddenly sucked into a medium sized hole.
Everything was black, then they heard something land with a thump beside them.
"Cas? Tris?" they heard Titus' voice.
"We're here." Said Cassie.
Suddenly a booming voice called through the dark.
"You have trespassed into our world. And you will pay the price!" the lights turned on and they saw that they were cornered. Behind them, there was a ladder back up through the hole.
As the creatures standing in front of them advanced, the triplets scrambled up the ladder.
One of the creatures caught onto Trista's foot, but them it slipped out.
"WE WILL GET YOU!!!" They heard the faint booming voice as they ran as fast as they could away from it.
As they rounded the corner to their house, they each felt something sting on their forearm. As they looked down, they saw that they now had a burn mark - red and raised - in the shape of a circle, with three coma shaped marks in it.
Now they were in trouble.