One day, without any warning, the ground in the middle of the city collapsed. At first, it was thought to be a massive sinkhole. Roads cracked, buildings tilted, and subway tracks and water pipes collapsed all at once. However, the collapse was deeper than expected. Beneath the crumbled ground, there were no underground cavities, no subways, and no closed facilities. There was only a massive hole of unknown depth.

People called it the 'Hole.'

What emerged from the Hole was hard to even call a living creature. They have no form. They have no color. Nothing is captured on camera. Yet, they clearly exist.

People called these 'Anomalies.'

When they pass by a person, goosebumps suddenly break out on the skin. Clothes flutter in a space without a single breath of wind. And in the places where they pass, people lose their sense of direction for no reason or lose their memory for a short period of time.

And a few seconds later—

People collapse. Some died, and some survived. The government and the military sealed off the area around the Hole. At first, it was a disaster response. Later, it became a military operation.

Thus, the Spatial Anomaly Response Unit (S.A.R.U.) was formed.