Reno and Hyde, the espers on sentry duty that day, were just on their way back to the outpost from the regular patrol when the detection device gave out a warning signal.
The device was made to detect miasmic beings, be they wraiths or beasts, up to a kilometer radius. It would send out an alarm and mark the location of the appearance. What made them temporarily freeze was that the warning signal beeped repeatedly.
Which meant there were multiple appearances of miasmic beings all at once.
"What, is it a horde? A stampede?" Reno took out the beeping device and they look at the screen closer, and felt goosebumps.
There were dozens of red dots on the screen, jumbled up so much that it painted the section where they gathered in a big glowing red circle. But what drained their blood was that those pulsing red dots were covering the area that was supposed to be their outpost.