Lin Mu's immortal sense sank down into the ground, and observed everything on its way.
In this, the first thing he noticed was the rich presence of Death Qi in the soil and rocks. This bothered him since using Immortal Sense became extra hard. He had to maneuver between the Death Qi to go downward but that wasn't possible in all parts.
It was okay if it was smaller pockets of Death Qi mixed in the soil, but when there was a large chunk that simply prohibited one, Lin Mu had to take the long route around it, causing his Immortal Sense to be strained.
His Immortal Sense was already the best among everyone here, and his control over it was also higher than most. As such, if not for him others wouldn't even be able to attempt the same.
Lin Mu felt like he had entered a labyrinth with no sign of the exit.
Still, he didn't stop and kept on going deeper and deeper.