The Invisible Tialian

In the year 2026 something began tearing down the world. Cities were being blown up and destroyed, as if some massive thing were crashing through it. But nothing was seen. Nothing was heard. It was just utter disaster. People panicked as this began happening to every civilization and even natural places such as mountains and valleys. Something was destroying it all. Clearly whatever monster this was, was invisible. But it wasn't invisible all the time, people had caught slight glimpse of something massive in the sky or crashing into a city. But as quick as they saw it, it vanished. This story begins in the year 2048. People started living underground and an organization called The DOTTD was formed. The organization was committed to seeing this thing and putting it to a stop. The story starts with a 17 year old boy named Travis. Travis lived underground like the rest of the human race. He has 3 close friends, Kaden, Marcelyn, and Alex. But as the monsters raging gets more intense, Alex had begun acting...strange.