This is a bit sadder than the others, and a bit closer to the movie version.
Year 3:
"Look, Hermione! My dad is going to come! I saw him!" Harry was standing across the lake with Hermione, watching Dementors draw closer to him and Sirius.
"Harry," said his best friend pragmatically, "you're going to die. You have to do something!"
"No, Hermione. My dad is going to come." Harry looked around expectantly, but the trees showed no signs of a hidden stag. "It doesn't matter. He'll be here."
"Harry…" She stopped, watching the dementors draw closer to the stricken body of her friend. They were gliding with a definite purpose.
"Harry," she began again, more urgently, "Harry, you're father is dead. You have to save yourself."
"NO!" He screamed. "He's going to come and save me. Just you wait!"
Hermione began to wring her hands, continually glancing around her. The dementors still drew closer to Harry's body, and one of them turned to look at her, it's dark, unseen face causing chills to course down her spine.
"Harry, you have to save yourself!" she cried in desperation. "Your father is not coming back!"
He stared at the dementors getting closer. Soon it would be to late. He found he had no strength left for a rebuttal. "Maybe you're right, Hermione," he muttered.
"Aren't I always?" she shrieked. "Now hurry and cast the charm!"
"Expecto Patronum!" cried Harry, but he was trembling and the last part came out as a stutter.
"Try it again!"
"Expecto Patronum!" Not so much as a drizzle of silver mist came out of his wand.
Hermione reached into the pockets of her robes. "Here Harry, have some chocolates!"
"What?"
"Professor Lupin told me you might need it!"
Harry ate quickly, as a Dementor crouched over him, slowly lifting it's hood back.
"Harry! Say the charm now!" screamed Hermione. "Hurry, before it's too late!"
"Expecto Patroooooonunununu…." His face contorted as, across the lake, the dementor administered the kiss. Harry's voice faded into a gurgle, and his eyes rolled into the back of his head.
"Hermio…Hermi.." he whispered, fighting the feeling that his soul was being pulled through his mouth. "Ki-ll meee," was his final wheeze. The boy who lived collapsed to his knees, and Hermione saw him gasp as his soul left his lips.
"Oh Harry, I can't do it!" she wept. "You might have been annoying at times, but you were my best friend, I can't kill you."
"Bugger that!" came a voice from behind her. A head crested with white blonde hair came out of the bushes. "Potter asked to die. I couldn't say no to that."
"Please, Malfoy!" begged Hermione, "You have to. I don't want him to live like this. Or half live. It's so horrible!"
"Couldn't disobey Potter's last request," smirked Malfoy. "Avada Kedavra!"
Hermione whirled around and collapsed into Draco, sobbing into his shoulder.
Not quite knowing what to do, he patted her hair, deciding that flinging her off after he had just killed her best friend would be a bit harsh, even for a mudblood. Besides, she smelled very good. Like pear.
"Hermione," he whispered, "It's going to be alright." He guided her stiff body back up to Hogwarts, where he led her straight to the hospital ward. He stayed with her the rest of the evening, like she was a child that he felt the need to protect.
In the days that came to pass, Harry would be mourned by his friends, and Ron, in his grief (or possibly his clumsiness) would fall off the astronomy tower. Hermione was left with no one but the blonde angel, who, in one night, had come to care for her more than he thought he could.
It wasn't until their seventh year, when they were dating and sharing a dorm room (as Hogwarts Heads are rumored to), that Hermione mentioned the lone night in third year.
"Thank you," she said, smiling at her boyfriend as he sat on the couch with her, an arm around her shoulder.
"For being the best, sexiest boyfriend ever?" Draco asked, smiling at her.
"Well, that too, but for that night when you killed…"
He silenced her with a glance. "It was what he asked for."
Hermione nodded. "I know. Thank you. You saved Harry and I that night. Thank you so much, Draco Malfoy."
"If I hadn't I wouldn't be your boyfriend," he said. "And I like being your boyfriend." He bent down and kissed her nose.
"I'm glad you like being my boyfriend," she said, "because I'm not going away."
"I'd never ask you to." This time, he kissed her on the lips.
Of course, that's not how it happened. Some philosophers have speculated on the nature of time, and have settled on a theory called the Trousers of Time, that basically, in any instance, the you of each parallel universe makes a different decision and heads down a different path. JK Rowling hasn't heard about the Trousers of Time, or at least the only part of Harry Potter's story that she discovered was in the other leg of it, the other universe, where Harry lived. Take heart, reader, that somewhere, in the Trousers of Time, it happened this way. But, in Rowling's world, that Harry Potter kid narrowly escaped, and lived on for another year…