Disclaimer: Not my characters. Darn it. All characters are property of JK Rowling.
The worst thing about fighting a civil war is meeting people you know on the battlefield. There is always a moment of hesitation, always a split second when the instinct for self-preservation wars with the repugnance of killing a familiar person, a person who you've passed in the hallways, a person with whom you've worked in classes. A person whose family you met at graduation. Afterwards, when the light has faded from their eyes and they are no longer distinguishable from the rest of the bodies strewn across the battlefield, you ask silently for forgiveness and hope to God that you don't recognize the next wizard you face across a wand. At night you try to ignore the ranks of former classmates who march across your subconscious. You try to remember that you're saving your friends and your family. Try not to think about their sons and daughters, husbands and wives. Try not to contemplate the life they would have had if you'd hesitated a little longer. As you reach to pull the vial of Dreamless Sleep from the drawer, you try not to notice how your hand shakes. As the potion takes effect, you try not to think about the fact that the same thing will happen tomorrow. And the next day, and the next…
Harry Potter doesn't take the potions that the Healers prescribe for him. He tells everyone that he doesn't want to risk fuzzing his thoughts and that he needs to be available and alert at any time. He uses glamours to conceal his bloodshot eyes and the circles under them so they don't worry. He doesn't tell anyone that he doesn't use the potions because they remind him of a Potions Master that he used to know. He doesn't say that without the potion he dreams of the Potions Master almost every night. Most of the dreams are nightmares. He sees Snape screaming at him across the potions classroom. He sees the gleeful look on his face as Snape held Sirius at want point and threatened to destroy Harry's newfound family. In most of the nightmares he sees Snape pointing his wand at Dumbledore, the only wizard Voldemort ever feared, and watches him calmly say the Killing Curse, unable to close his eyes or turn his head. These dreams he's used to. He's had these dreams since the battle at Hogwarts. It's the new dreams that worry him, that make him ashamed as he wakes up alone in his tent, sweaty and out of breath. On the mornings after these dreams he forces himself not to think about the dark, velvety voice or the long, talented fingers tracing patterns across his body. When he returns to the battlefield, he tries to tell himself that he is not scanning the face of every person he comes across, praying that he does not see Snape at the other end of his wand.
He doesn't understand where the new dreams come from. Harry doesn't remember ever having feelings besides intense dislike for the pale traitor. After Ginny, he never had the time or the inclination to return to her or to start a relationship with anyone new. He cannot remember ever being attracted to another man before. The idea itself doesn't bother him, but he is disgusted by the fact that his subconscious has fixated on the man that is his second most hated enemy in the wizarding world. He tries not to think about the look on the man's face at their last confrontation – about the desperation that had graced his harsh features before being replaced by utter rage. He tries not to remember that Snape could have killed him and didn't. That Snape, in a bizarre way, saved his life again. He could have Stupefied him and taken him directly to Voldemort. He thinks about attempting the Killing Curse and how easily Snape had blocked it. He wonders if he has enough hate now to cast it, or not.
He wonders which would be worst.