Professor Bill Neigh's Theorem of Hammerspace

Professor Neigh explains to Spike how his letter sending, hammerspace induced, fire breath may not always work properly.

Professor Bill Neigh is stuck watching the Equestria games with his family when he notices a past project of his, Spike, unable to breathe fire. He can't help but think his meddling with hammerspace physics and magical theory may have been responsible for this.