The conflict arises when Leon discovers he is not alone. Another subject has received the same treatment—a "hyper-intelligent" antagonist who is evolving just as fast. The story becomes a chess match played with supernovas of thought, culminating in one of the most chillingly logical conclusions in SF history.
Leon gains total mastery over his own biology, becoming aware of his glandular secretions and the very neurotransmitters firing during his thoughts. Understand By Ted Chiang Pdf