I need a bit of help here.

The inciting event of my current story involves a large group of teenagers agreeing to train themselves for a reckless, dangerous trip into a cave to retrieve the most powerful energy source known to the world (and the most heavily-guarded). Most of these kids are down-to-earth, realistic-thinking kids that are smart enough NOT to do something like this… and yet they end up doing it. I'm struggling to figure out how these kids end up signing up for a task that is–more or less–voluntary. Any suggestions? (if you need more information, I'd be happy to give.)

Thanks for the help, it gave me a great idea!

Like I've said, a large group of kids are sent into a cave. Bit of backstory: they learn about a magic force that is killing the universe (this turns out to be fake, but they don't know that). The main villain (supposedly an ally) has to send these kids into a cave. I plan to do this by a threat. However, I don't want the threat to be very obvious to most people, so that only a handful of students actually understand it. Does anyone have any idea on how to conceal a threat inside a mess of details?

It's hard to explain, but an idea's been conceived, so I don't need any more help.