Good cliffhanger stories are engaging because they play with your emotions. They build up tension throughout the story, and then at the end, they don't give you the resolution you expect. This makes you feel a range of emotions like excitement, anxiety, or curiosity. Also, they often leave some loose ends. In a cliffhanger, not all the questions are answered, so your mind keeps racing, trying to figure things out. For instance, in a science - fiction cliffhanger, a new discovery is made but its full implications are not clear, and you're left wanting to know more.
Well, the element of surprise. A good cliffhanger throws something unexpected at you at the end. For example, in a mystery story, the detective might be about to reveal the killer, but then the chapter ends, leaving you desperate to know. It also creates anticipation. You start to imagine all the possible outcomes, which keeps you hooked. Like in a thriller, when the hero is in a life - or - death situation at the end of an episode or chapter, you can't wait to see if they survive.
The key factor is that they create a sense of investment in the story. When a cliffhanger occurs, it means you've been following the plot and characters closely enough to care about what happens next. Cliffhangers also introduce a sense of urgency. You feel like you need to know what happens right away. In a story about a group of adventurers lost in a jungle, if the end of a chapter shows one of them being attacked by an unknown creature, you are immediately drawn in and eager to find out if they will be okay. And cliffhangers can be a great tool for writers to keep readers coming back for more, as they leave you with a feeling of incompleteness that can only be resolved by continuing the story.