The Island of Destiny

It takes you about half an hour to hike out to the river, but once you have make it there you feel so much more relieved. The cool drinks of water feel like nectar running down your throat, and you just cannot seem to get enough.

As you gaze upwards from your blissful drinking, you notice something strange hunched along the bank. It is a dark figure, oddly-shaped, and you can't tell exactly what it is. Then in the blink of an eye, the figure vanishes and you are left wondering if it was ever there.

Should you go over to where you saw the dark figure or just let it go?