It's just the situation which develops into the plot, or rather, the situation from which the plot develops. There's an element of suspense, a sense of potential, of possibility, of anticipation. That is, by withholding what they want, we entice them. Sort of like with men. That's the situation.
Civil war breaks out in an elite boarding school.
That's a quick, clever, resonant TV-Guide sort of summary. Conflict is definitely the key, because conflict is potential, conflict is danger, conflict is suspense. It must imply conflict. It must imply potential. It must imply tension.