Complex sentence: The police arrive, only to find out that there's no body in the gully, only that there is a trail of blood that leads a hundred feet south, where Shivers climbed out of the gully and went into the woods.
Split into simpler sentences: The police arrive, only to find out that there's no body in the gully. All that's there is a trail of blood that leads a hundred feet south, and then Shivers climbed out of the gully and went into the woods.