So what I want to do is this.

The first part of my quest ends with you discovering the body of a NPC, which then prompts the quest giver to force dialogue with you and finish that part of the quest line.

See what I mean? Is there a script or package that can do that?

So what I mean is essentially this.

After completing the objective of this stage of the quest you happen upon a dead body of hunter.

Suddenly the quest giver swoops in out of nowhere and forces dialogue with you, ending the quest and starting the next one.