The hallucinations caused by Dreamless Sleep frequently take the form of movement in the peripheral vision, and mistaking things that are really there for things you might see in dreams or memories. So: seeing a second-year out of the corner of your eye, and thinking you see something much more dangerous.

I can understand why you want the Dreamless Sleep. Remember, I was there, too. Is there someone you trust who you can talk with? Finnigan, or Su Li?