Sure, here is a riddle sequence designed for a 12th-grade average student that loops back to the original riddle:

Riddle 1:

I speak without a mouth and hear without ears. I have no body, but I come alive with wind. What am I?

Riddle 2 (Answer from Riddle 1 leads here):

I can fly without wings. I can cry without eyes. Whenever I go, darkness flies. What am I?

Riddle 3 (Answer from Riddle 2 leads back to Riddle 1):

I run, yet I have no legs. I can float, yet I have no wings. What am I?