In the late 1920's, pulp novelist William Wallace Cook wrote a book outlining 1000+ possible plots. Someone put it online, with links between the various plot points:
https://garykac.github.io/plotto/
Select a starting point, & follow the numbered links to see the possibilities. You can follow the links towards the beginning, or towards the end. I'm not really sure how one is supposed to choose a starting or stopping point; I suppose you just pick a spit you like.