Below: almost the last thing they ever saw.
Exploring A Cave When Your Only Light Goes Out

This is a video from ill-prepared spelunkers James and Edward of Youtube channel ActionAdventureTwins exploring a water-filled cave when their only headlamp goes out. Apparently they had others, but the batteries died and they kept going deeper anyways. Really? You ought to have your adventuring licenses taken away! Thankfully for them, the duo is able to retrace the relatively linear path back, and eventually run into another group of explorers, who should have kicked them back into the dark and run away to teach them a lesson.

Keep going for the video, lights out at 11:00.