When my boys were little they asked my husband to read and reread this little book. I wish I still had it. It was about a father and son skeleton going out on the town. I can only remember the start, "It was a dark, dark night on a dark, dark street in a dark, dark town..." You get the idea. My husband would read it to them in his dark, dark voice.
I always think of that book for some reason when people talk about the dark moment in their novel. Movies and TV shows have dark moment too. You know that point in the story when despair and desperation sets in. Everything that could go wrong does and maybe a little bit more. There's no way out for the good guys. The best dark moments have physical and emotional dangers ready to pull the protagonists into the abyss of failure. The dark moment can only be conquered only by the hero or heroine making a decision or taking a chance that requires sacrifice of some sort.
I'm in the middle of writing the dark moment in my current WIP, War Dragon, the sequel to First Dragon. In a series with an ongoing saga like my current works, there's a dark moment in each book. But each book also builds toward the greater dark moment of the series. The good guys are losing ground in each book. Which brings me to the next point.
The main characters have to be tortured, hurt, trapped torn apart or something equally terrible to create a compelling dark moment. I'm cringing as I type in the horrors visiting my characters in the next 15K of manuscript. They won't all survive. Now that's dark.
Do you have fun writing the dark moment or does it hurt you to hurt your characters? Have you ever watched a TV show and guessed at what time the dark moment will occur? Usually about 45-50 minutes in, I think. Have you read books where the dark moment was too easily solved?