I tried to make the video easy to follow, but you might care to read the sypnosis before or after you watch it.

This video picks up where the seventh book left off, with the exception of Snapes survival. Still considered by many as a traitor, the potions master can find no work outside of Hogwarts. Hermione Granger has also returned to complete her final year of school. She applies for an apprenticeship with Professor Snape, believing that now his spy status has been terminated, he will prove kinder.

He is, decidedly, as vile as ever. Nonetheless, Hermione works hard. She listens aptly as he instructs her, teaching her varying wand movements and most importantly, potion instructions. He is quick to point out her inaccuracies. (He even blows up her potion out of spite at 00:38-00:48) He runs her raged, and Hermione is becoming frustrated by his hostility. She eventually confronts him, and he tears into her about discipline and effort. She begins to cry, and feeling he may have gone too far, Snape walks out.

That night, Severus dreams of Lily, who tells him he is ready to let go of his love for her. When he wakes, he feels weak and lost. The next day, Snape approaches Hermione and asks for a word. Alone, he apologizes for his behavior. She forgives him, touching his hand in reassurance.

The school year goes on. Under better terms, Snape continues to teach Hermione. She regards him as a friend now, and is consequently nice to him. This attitude is so foreign to Snape that he is confounded by it. He tries to maintain a cold manner, but she has become steadily immune to his tactics and politely challenges him.

Months pass (January, February, March, April, May), months of education, arguments, and personal growth for Severus and Hermione. Hermione is doing outstandingly in potions but an even greater success, she is fond of Snape. Severus is beginning to see Miss Granger as a woman, no longer a beaver-faced showoff.

One afternoon, Hermione peaks her head into Snape's and invites him to dinner at a restaurant outside of school. He doesn't answer at first, wary, but that evening, at the restaurant, he walks up to Hermione's table. They share enjoyable discussion, about everything except school.

Suddenly, in the midst of their meal, an ex-Death Eater spots Severus. He hovers near their table, and Hermione spots him. Snape spins to look, but does not react fast enough to prevent from being attacked. A duel ensues, however Snape manages to defeat the Death Eater.

That evening, the pair return to Hogwarts. Hermione and Severus sit together, and she thanks him for saving her. He says that he did nothing short of put her in danger. She exclaims that he was wonderful; he protected her. Hermione touches his cheek.

Severus panics and gets up to leave. She calls to him and asks him to please, stop running from her. He pauses, and Hermione stands, putting her head on his shoulder. He turns and tells her that he cannot. She assures that he can. He says it would be self-destructive. Everything worthwhile comes with risk, she replies. He states that she is too young to know what she says, and she retorts that he is too old to talk her out of it.

What does Severus do next? Well, why dont you see for yourself? (less info)