Heaven's Hellfire

Around three minutes into my walk, when I was out of sight of people and cars alike, I slowed. The tugging had grown to almost an ache in my stomach. Eh, probably just a stomachache. I managed a few more steps, and the tugging grey more painful with every step.
The wind began to blow through the trees, scattering leaves everywhere. I swear, the sun dropped in the sky as clouds darkened and covered the sun. The shadows around my feet began to grow. Then, to my horror, I began to sink into the ground, dissolving into shadow.