The Gaunt Solution
Harry stood beside Draco in the middle of his living room, dressed only in a towel, and resisted the urge to cower. Just. Snape, once again, perched black and bat-like on the low wall surrounding the pleasant watercolour cottage that hung above Harry's fireplace. The expression on his face indicated that he expected to be infected by terminal kittens and cream teas at any moment and was ready to retaliate.
"Your taste in artwork is as abysmal as your taste in godparents, Potter," he said disdainfully. "Now kindly explain yourself before I report both of you to the Headmistress."
If Harry had thought it was hard trying to convince Ron, Hermione and Andromeda that he wasn't insane (and was, in fact, the soon-to-be Master of Death), it was nothing compared to the grilling he was subjected to by the portrait of one Severus Snape. The man was a Slytherin to his core and had been a spy and double agent for most of his life. He was the sort of person who wouldn't even trust his own reflection without photo identification, wand scan, and full background check.
The only good thing coming out of the experience was the unexpected insight Harry was getting into his mother's childhood. Snape clearly knew that the best way to confirm the truth of Harry's words was to dig for details of his life with Lily before Hogwarts that would have gone to grave along with Harry's mother when she died.
"What was her favourite Muggle sweet as a child?" he snapped. And, "How often did I transfigure her repulsive sister's doll into a badger?" Between them, Snape and Lily were revealing the secret story of an unlikely friendship between an angry, lonely little boy and a pretty, middle-class little girl who couldn't quite fit into her ordinary Muggle family.
They heard about little things – the colour of the hair ribbon Snape illegally Accio-ed for Lily when it fell into the park's stream. The brand of toffees the two of them nicked from old Mrs. Weatherbin's handbag after she called Snape a grimy little gutter rat. The scent of the shampoo they used to wash the Evans' cat after an unfortunate potions experiment when they were eight. Harry passed Lily's words on in a hushed voice, captivated and incredibly grateful that the other Marauders had been banned from saying anything to put Operation Persuade Snape To Help in jeopardy – although Lily's and Remus's mental gagging techniques were being sorely tested at times in spite of this.
When it finally seemed that Snape was running out of questions, Lily sighed in Harry's mind and said, :-Let me take over, Harry.-:
Snape was still hunched forward, scowling suspiciously at Harry as he stepped aside to let Lily take over. His body gave the now-familiar shudder (causing the already precariously balanced towel to slip down a little further) and Harry's consciousness was suddenly squashed up in the back of his own head with the other Marauders.
"It's me, Severus," Lily said, stepping up closely to the painting and looking warmly into Snape's eyes.
Harry, frankly, thought that that was the least persuasive argument since Draco claimed that the last chocolate frog should be his because his hair rocked and Harry was a Gryffindor arse. Snape, however, stared into Harry's eyes for a few long, disconcerting seconds before sitting back on the wall looking shell-shocked.
"How did this happen?" he whispered.
"You mean I have to go through it all again?" Harry whined, taking over again. "Wasn't a million times enough?"
"Welcome to five years of teaching Longbottom Potions, Potter. And hyperbole does not suit you. If used, it should be applied with razor wit, which you are sorely lacking."
Harry stared at him blankly. "You what? Seriously, it's like Potions all over again." He glanced at Draco. "What's he saying? Is he talking about some kind of hair product?"