"You want to do what?"
"Just talk to him for a few minutes," Harry pleaded to McGonagall. "It's very important."
"Please, professor," Hermione said. "It's about the Athrimo potion."
"And you think Severus could help you with that?" McGonagall asked.
"Yes, we do," Harry nodded. "You've worked with him; you know how brilliant he was with potions."
"Of course he was brilliant," McGonagall agreed. "However…can you be sure he'll be willing to help you?"
"He was on our side nineteen years ago," Harry said firmly. "He won't be switching sides now."
"Very well," McGonagall nodded. "You have my permission. I'd take you up to the office myself but I was just on my way to deal with Peeves. Seems he's gotten a hold of some suits of armor…"
"Thank you," Harry said earnestly.
"Password's 'Ice Mice'," she said curtly as she headed away in the other direction.
"You know, mate, she does have a point," Ron said as the three started towards the gargoyle they knew hid the headmaster's office. "Just because Snape was on our side nineteen years ago doesn't mean he's all of the sudden our best friend. Sure, I don't believe he's going to go run off to a portrait frame in Claridina's hideout and start helping her, but do you really think he's going to help us? I mean, we're no Dumbledores."
"We'll just have to hope for the best," Harry said.
When they reached the gargoyle, they gave the password and stepped onto the spiral staircase that appeared before them. They climbed until the reached the door with McGonagall's name on it.
The one occasion prior to this when Harry had been in McGonagall's office, Snape's portrait had been empty, as had Dumbledore's. Fortunately, though, when he pushed open the door today, he saw the familiar face of the greasy-haired man with the hooked nose sitting in his canvas. As Harry, Ron, and Hermione entered, his eyes gave the slightest of flickers,
"Er, hello," Harry said hesitantly, stepping in front of Snape's portrait.
Snape didn't reply.
"Um, well, I don't-I don't know if you hear about what's going on outside the castle too much from McGonagall," Harry started. "But there's some awful things going on out there."
Again, Snape remained silent. Harry looked back at Ron and Hermione, who both gave him urging looks.
"There's another dark wizard coming to power," Harry went on. "Or rather, a witch. Her name is-"
"-Claridina Wretermoust," Snape finished, finally speaking in his soft, oily voice.
"You have heard of her then," Harry said. "Brilliant. Well, she's getting really powerful, and I don't know if you know this, but she's rather good with potions. More than good, really; she's unbelievable. That's how she's leaving her mark, and that's her biggest weapon."
"She was remarkable back when she was young as well," Snape said coldly.
"You-you knew her when she was young?"
"She stayed at the Malfoy mansion," Snape said. "She was hand-selected to study the Dark Arts first hand."
"Right, right," Harry nodded. "Draco did mention that."
"She tried to persuade me to help her with creating her own blends," Snape continued. "But I was far to busy for the likes of a silly young girl so I refused. I heard it in passing that she was going out to another for lessons, however."
"Do you know who?" Harry asked.
"No. It was of no importance to me."
"Right, well," Harry nodded. "She makes her own brews, and she also succeeded in making a large vile of Athrimo."
Snape looked up.
"She didn't get a chance to use it," Harry said quickly. "She placed the bottle with one of her followers and sent him to a Quidditch match to release it, but the Ministry caught him before he got the chance. There's almost nothing known about the potion, and when we tried to find some more information, we had no luck. So we-we realized that you were our only hope. We visited your home in Spinner's End and-"
"You trespassed in my home?"
"We're sorry," Hermione said. "But it was all we could think of."
"We only looked at the books in the living room," Harry assured him, trying to push the box they had found of him and his mother to the back of his mind. "And we did find something helpful in one of them."
Snape just stared at him.
"In the book, though," Harry continued. "The part about the Athrimo…it was marked. And circled."
"And you assume it was my doing?" Snape asked.
"It was your house."
Snape nodded.
"Why was it marked?" Harry asked.
Snape didn't answer. He looked over at Ron and Hermione, who were standing behind Harry.
"Ron," Hermione whispered. "Let's wait outside."
"What? Why?" Ron frowned.
"Just come on," she said, taking his hand and pulling him out of the office.
"Why was it marked?" Harry asked again.
"The Dark Lord," Snape spoke slowly. "Was very gifted."
Harry frowned, but didn't say anything.
"He heard about Athrimo," Snape said. "And he ordered me to make an entire cauldron of it."
"When was this?" Harry asked.
"During his second reign," Snape replied. "Right after he rose again. He wanted something deadly that he could use but would still allow him to remain out of the Ministry's radar. He knew about Athrimo from that blubbering fool Slughorn; probably told him about it over a bottle of wine."
"So you made it?" Harry asked.
"I did what he ordered me to," Snape said. "His plan was to release it at the Ministry and then begin his takeover."
"What went wrong then?" Harry frowned.
"As I said, the Dark Lord was very gifted," Snape went on. "Cruel, evil, unforgiving, yes. But gifted. No on can or will ever deny that. But the Athrimo potion was practically unheard of even then. All he had learned from Slughorn while he was at school here was that it was the deadliest potion to date. He didn't know how to destroy it."
"It can be destroyed?"
"A handful of mandrake leaves will soak away all the poison that makes the brew so deadly," Snape nodded. "I figured that out during my school days, but even great Potion Masters have not yet found it out. I slipped the leaves into the potion and all that remained was water."
"But wasn't Voldemort mad?"
"Of course the Dark Lord was mad," Snape snapped. "I was punished most severely for failing to make the potion successfully."
Harry could only imagine what sort of torture Snape had to endure for that doing. He admired the man, though, for going to such lengths to assure that the potion was destroyed.
"In the end, however," Snape continued. "Before the Dark Lord could force me to re-make the potion, I persuaded him that the use of the potion would've been…unwise."
"Unwise?" Harry frowned.
"I explained to him that the use of the potion to take out the entire Ministry would not work in his best interest," Snape nodded. "If the entire Ministry fell, we could no longer cover up that he was back, and Dumbledore would not continue to be thought of as a sham. In no time other Ministries in the continent would unite and he would have to face them all before he had gotten a chance to get back the entirety of his followers."
"He never did anything else with potions, though, even after he was discovered at the Ministry that night," Harry pointed out.
"I managed to convince him that the true way to accumulate real terror was to stick to his spells: killing curses, torture and the like. Potions took time and were far to clean."
Harry nodded. "You saved a lot of people. If Voldemort did have access to that potion and took out the Ministry back then, it wouldn't have mattered about the other countries and you know that."
Snape just looked at Harry with his cold eyes.
"You've helped us a lot," Harry said. "Thank you. I'll just-er, go now."
Snape gave a short nod. Harry turned to head out of the office, but before he left, he stopped in front of the frame where Dumbledore's portrait hung. The frame was empty though. Harry opened his mouth to ask about his whereabouts, but before he could, Snape said, "He visits his sister's portrait at the Hog's Head often, from what I gather."
Harry nodded, and then without a word, he walked out of the office.
"Well?" Ron asked as Harry shut the door behind him. "What did he have to tell you that was so important that he had to kick us out to tell you?"
"I'll explain later," Harry. "We should be getting back to the Ministry."
"He's right," Hermione said as Ron opened his mouth to protest. "We'll talk when we get back."
As Harry followed the other two out of the castle, back towards Hogsmeade, he wondered just where him and all the others would've been now if they didn't have Snape. His contributions to the downfall of Voldemort had been immensely significant, and even though Snape clearly wanted to keep the number of people who knew that low, Harry knew the man would always be a hero.