Okay, so you've got the Build-Up (see Endings, Part 1) covered. What comes next?
The Black Moment is the point in the story where it appears "all is lost". The situation is hopeless. The guy won't get the girl. The virus will spread and turn the entire human race into zombies. You get the point.
The checklist here is pretty basic:
- Does all genuinely appear lost?
- Has the hero or heroine turned to walk away?
Answer "yes" to both of these? Congratulations! Your Black Moment is sufficiently bleak (incidentally, you might also want to seek therapy. Just saying.). Stay tuned!