I OWN NOTHING! Harry Potter and all related affiliations are the property of J.K. Rowling. I'm just an innocent fangirl. Enjoy :)
Severus and Lily combed the woods for days, searching for Harry and his companions. They followed every possible lead, every scent, and every trace of recent spell activity. Eventually, they found themselves encamped in the middle of a wood. Lily set up defenses around their campsite, then together, she and Severus gathered water from a nearby stream.
As he knelt down by the side of the stream, Severus heard a twig snap right behind him, and before he could drop his canteen and reach for his wand, a voice spoke:
"Don't move a muscle or I'll off you, I swear. You've already given me plenty of reason."
Harry Potter shoved his wand tip hard into the back of the Potions professor's head, letting him know just how dire his circumstances were.
"As usual Potter, you've come to the wrong conclusion. However," Snape spoke calmly, squeezing Lily's fingers for comfort, "I would strongly advise you not to remove your wand from its present position, as I am carrying a very important message for you from Professor Dumbledore, and if you don't follow my instructions very carefully, I'm afraid I will be unable to deliver it with the urgency which it deserves."
"What are you playing at?" Harry spat at him. "If you think for one second your mind games are going to save you this time, you've got another thing coming."
"I can assure you," Severus replied, maintaining the calmest voice he could muster while simultaneously holding Lily's gaze, "you are the only person about to play a 'mind game.'"
Lily looked at him quizzically, and Harry was unsure how to respond. Together, the two lovers stood and turned to face their captors.
"I assume that you recall as well as I do our short-lived private lessons?"
"What of them?" Harry questioned, remembering uncomfortably the night he witnessed Snape's worst memory. He wondered why Snape would choose to bring up the subject when it was he who cancelled the lessons due to their revealing nature.
"Do you remember the spell I used?"
"Yes," Harry responded, wondering where this was leading.
"I want you to use it on me," Severus spoke slowly.
Harry was certain that Snape had gone mental.
"You've already encountered that which I had intended to keep hidden. Anything else you might encounter that you disbelieve, you may discuss with your mother to verify its authenticity," Snape continued. "By the way, I very much appreciate the quizzical looks on your friends' faces."
Harry had never told Ron or Hermione about the memory Snape had unwillingly shared with him. It was the one memory Harry knew of that made him admit that his father was less than the picture he'd always been presented with.
"What would you stand to gain from it?"
"The satisfaction of knowing that if you do decide to kill me, I'll die having fulfilled my life's ambition," Snape replied quietly, flashing Lily a small, sad smile.
"And what would that be?" Harry questioned, beginning to feel foolish.
"Telling your wonderful mother how much I've always loved her."
Harry was taken aback. He looked at his mother to see what her reaction was, and the look in her eyes told him everything he needed to know.
"Whenever you're ready then," he responded, relaxing his grip on his wand a bit and taking a step back.
Severus turned to face him, tucking Lily's arm under his. He closed his eyes and took a deep breath.
"Legilimens!" Harry shouted.
He was immediately engulfed in an unfiltered sequence of Snape's memories. The first was of Snape informing Lily that she was a witch. He watched with pleasure as Snape tormented his aunt Petunia, then only a child. He was then thrust forward into a memory showing the two of them laying side by side under a willow tree, his mother laughing and Snape smiling broadly. Harry had never seen the Severus Snape he knew smile; he never even thought he knew how. He then saw Severus reporting the Prophecy to Voldemort. The horror in his eyes when Voldemort named Harry Potter caught Harry off guard. The memory flashed forward to a conversation with Dumbledore, and Harry listened intently as he learned of what made Severus switch sides. No one had ever believed Severus's loyalty to Dumbledore, but now Harry understood why Dumbledore had stood by him; Lily's life meant more to him than his own. As Harry stood and watched the last memory unfold, he finally realized how wrong he had been. Snape had spent his life protecting Harry in the event that Voldemort returned; and he had forbidden anyone to know about it. Harry knew there were more memories for him to see, but his strength was failing, and regrettably, his spell faded.
He stood gasping in front of Severus, Lily torn between which of the two needed her more. He looked into Severus's eyes and offered him a small nod.
Severus was also gasping for air, but he was determined to let the boy see everything; he owed it to him for six years of false impressions.
"Again," he whispered.
"Legilimens!" Harry shouted, a bit softer than before.
This sequence of memories started with Severus walking through the Potters' house after Voldemort had killed James and presumably Lily. Severus's heartbreak was almost too much to bear. He was pulled immediately forward to Severus administering a potion to Dumbledore in an effort to counteract the effects of one of Voldemort's horcruxes. The ensuing conversation knocked the wind out of Harry, and he nearly lost his grip on his wand as he first heard Dumbledore tell Severus he must kill him, followed by a flashback to the night on the Astronomy tower. Tears streamed down his face, but he gripped his wand resolutely as Snape's final memory began. Severus's words rang in his ears as he continued watching. "So when the time comes, the boy must die?" Dumbledore's lack of emotion as he continued speaking of Harry's fate stung, and he found himself once again questioning whether he had ever really known who the Headmaster was. His last words latched onto Harry's heart and dragged him back out of Snape's memories once more.
"Yes, he must die, and Voldemort himself must do it. That is essential."
Harry collapsed on the ground, gasping for breath, tears streaming down his face. He looked up at Severus and saw Lily standing over him with her arms around him.
"I guess we both know what it's like to be a pawn in someone else's game," Harry said between gasps.
"You understand what you must do?" Severus asked, swallowing hard around the lump in his throat. Harry had become the son he'd never had, though he loathed the half of him that was James Potter. Hearing his fate once had been hard enough. Hearing it again and seeing its reaction on the boy's face made him feel as though all of his efforts had been for nothing. The woman of his dreams was standing over him, and in just a few moments, he was certain that she'd have reason to never speak to him again.
Harry nodded, realizing as he did so that he had somehow always known it would come to this. All of his dreams, his visions into Voldemort's mind; this was the reason why. He stood up and looked over at his friends. He had no idea what to say to them. He knew they were still confused about what they'd just seen, but he wasn't sure how to explain it to them.
"What I must do now is something I must do alone. There is no one who can help me. However," he said to them, looking in their eyes as he did, "I can assure you that if you follow this man, you will be safe, and he will lead you to victory."