if you are going to create an epic narrative you should have at least very detailed accounts of bearings and lengths of travel so that readers can plot out the course and then find out you've been doing a dot-the-dot drawing the entire time but that's just me
Let the heroes' travel end in tragedy, unable to find the vital artifact that can save the world. "Can anyone solve this conundrum? Could some great being we cannot even imagine, told our story in every detail, see what all of our great sages have missed?"
And if you connect the dots it's the outline of a dog and the artifact was located at the dog's eye.