Note: this takes place sometime between Snape's third and fifth year, before the "Snape's Worst Memory" incident.
She is blind. Her green eyes, wide and curious, view the world with innocence and experience alike. She sees it all.
All but him.
He is beside her, the always friend. Through thick and thin. Nothing can ever come between them.
Once, he liked it that way, but now it is different.
It is a quiet, lurking hunger. Some would call it desire; he will not. She is what he cannot be. She has what he does not, would never. She completes him, like two sides of the same coin. Her side glitters in the sunlight. His is dull with darkness.
She leans over the cauldron, glaring into its depths, then turns to her textbook, flipping pages with impatient fingers. She is flushed, freckles blending into skin, skin clashing with hair. She will not look at him for help. She is, after all, the potions prodigy.
He already knows the problem and its solution.
But she cannot see it.
He keeps to his cauldron, watching her through the veil of his hair. Inky lank strands that prevent self-betrayal. The others cannot know. They have to remain blind.
He only wants her to see.
She raises her hand. “Professor Slughorn?”
The doddering old fool totters over, preening to be addressed by Lily Evans. He takes no effort in hiding his favouritism, though no one seems to care. If any professor is to have a favourite, it has to be Lily. She is always the favourite.
Snape watches them, chopping his daisy roots, trying to ignore the whispers and laughter of Potter and Black. They watch, too, planning, devising new forms of torture. He keeps his gaze upon Lily, and feels safe. She is his lone shield against their jeers, their hexes. She stands against them when he is weak. They will listen to her. Until she is out of sight.
Out of sight, out of mind.
Slughorn must have given an acceptable answer. She continues with her work, the flush fading as confidence takes reign. He takes in the tilt of her head, the way strands of hair free themselves from restraint, hanging in tendrils down her back. He sees these things and smiles.
Then she looks up. The hair cannot hide him from her eyes.
They see only the smile, the friendship, the encouragement to find the solution.
Those eyes glance away, back to her work. The air smothers him. The darkness grows around him. He cannot look away from her, from all the things she is, could be. He knows what this means, what he wants her to see. Please look one more time. Just once more.
But she does not, and the class ends. She is to go to another. Without him.
She says goodbye, the smile in her eyes, knowing they will meet later to talk, to do their homework, to do what friends like them do.