Standard disclaimer applies: it is all JKR's.
Because he watched another witch, before: but knowing that things are not always what they seem at first sight, and imagining – in our safe land of fan fiction - that those looks weren't the last ones, and that there wasn't only that one witch.
And because, despite the beautiful tales that help us after DH, that end comes back often, so real and cruel, to the memory.
Many thanks to Whitehound, as ever, for her unique and precious help with the language and, still, with everything.
He had witnessed too many awful events, and horrible people, too. He was so tired of being both a useless witness and a useful observer, of being forced to do, or not to do, because of the constriction imposed by his vows, things that his whole body ached to be allowed to do, or struggled to reject doing. Many times he had been forced to be a mere witness, too incapacitated by his oaths to do something different, to change in the slightest the terrible events happening in front of his eyes.
This time, however, he could be more than that kind of watcher.
He had had this woman under his eyes since the time when she was a child, but to look at doesn't always mean really to see. For some time the object of his current wonderings had inexplicably become mysterious and silent, and so, through his stare, he was trying to understood how this change had begun.
He remembered the times when he was a teacher, the different ways in which he looked at the students; at this former student, too. From the frequent glaring of his eyes everyone assumed that he watched them with annoyance, to say the least, and the amused expression that sometimes showed in a flicker of a facial muscle or a curve of his lips was easily misjudged as being meant only as a mocking one. Few, perhaps no-one, knew why he had for too long a time been unable to wear a different display of the true feelings that he still experienced, despite his fateful, doomed journey through life.
There had been a time, when Severus had been a child, when he was able to be the first to approach a person, another child, to start a new friendship. In those days his appearance wasn't handsome, his behaviour was shy, his clothes weren't of his choice and they were of the wrong size, but his heart and his life were still free: free-living, free-dreaming.
Now he could no longer dream nor approach anyone with trust: not when the friends he had chosen in Slytherin after having been put among them by a magic artefact had revealed themselves as bad friends; not when nobody outside Slytherin had given him a different possibility of fellowship, since for them it had been easier to bully him and keep their distance; and not after having lost, with his worst choice, the only person for whom he had cared and hoped to be cared for by.
But now he was watching the witch, struggling.
She had been with him for many days, after the end of the battle, waiting for his recovery with an incessant vigil. He remembered very few moments from those days, and his memories weren't nice ones. So, for a none-too short period, he had connected her presence with his suffering, not with his healing, and it was only lately that he had perceived hints of a different approach.
He was recovering in the castle, the centre of everything; a place where he had lived a miserable year, that last year when he had been sure he was near to a deserved peace, through an end of all his miseries that had seemed unavoidable. So his first thoughts, when he had regained consciousness, had been of disbelief, and also of angst: life hadn't seemed a grace or a miracle to him, but had felt more like a renewed burden which he hadn't asked for.
And, still, someone must have thought to save him few instants before his death, going on without respite, later, in a battle that he hadn't acknowledged until now as his.
Now, however, the castle was reawakening, like him, to a new life, stronger than the first. And to discover that someone cared, truly, and wasn't discouraged by a bad word, or by many strong words, was a warming surprise to him. A surprise that was giving him a new object for his angst, realising the blindness with which everyone had looked at him before, chaining him to his guilt and to his destiny more firmly than the vows which he had taken.
He was still watching the witch, thinking that now perhaps he could be free from his chains.
Lately she had become accustomed to go to the garden, often at the end of a busy afternoon, to take a walk or some rest; lying with a book to read, or simply enjoying the last warmth of the sunlight. Just now he had seen her walking slowly under the porches and then outside of the castle, in the open spaces around the ancient building, quickening her pace as if the wildness and the nature around her could give more energy to her feet, too.
He didn't give a further thought to his own newfound capacity for whimsical comparisons, which was the least of his new habits, as far as he understood them; but continued to watch her, in full sight through the open window of his room.
She stopped and transfigured a bunch of leaves into a soft blanket, and settled herself on it. Dressed in robes - a new tendency of hers, this one – she reminded him of a charming fairytale maiden even if, luckily, she wasn't a princess nor a sleeping beauty.
She was a witch who had fought hard to keep herself safe in this enchanted world, and she knew, even if not so deeply as he knew it, that the magic of this world wasn't a fairytale written for children. Beautiful, fascinating girls who grew up as princesses, loved and admired by everyone, leading their observers to think nothing but the best of them, weren't his kind of enchantress anymore… he had learnt this, at last, and perhaps not too late.
During the last few months, after those first meetings where the awkwardness between them had been such a strong barrier, a new, supportive companionship had been born. So he decided to join her, to enjoy the sunset next to her when she would awake from her little rest, and perhaps to say something different, this time, something that he was finally free to say without regret.
With his long strides he reached her side, and saw that she was so deeply asleep that his movements hadn't been noticed. There was a tree that was comfortable to lean on, so he sat and waited.
A movement, then a loud whimper, distracted the wizard from his thoughts, and he saw that the witch was dreaming: not sweet dreams, however. He approached her uncertainly, but seeing that she was trembling and struggling so hard he did it: kneeling and taking her in his arms he woke Hermione, softly speaking reassuring words.
She blinked, unaware, and then met his eyes with relief. Only after some time was she able to speak, and to explain the same old nightmare that accompanied many of her nights.
He had known what she had endured before the end of the war, and until this moment he had been relieved to have been spared the witnessing of those moments, at least. But he also remembered that night, when he had sent his silver doe to deliver the sword to the Boy. Hidden near their tent, unnoticed, he had perceived a soft sound, then muffled movements. Under the light of the moon and through the fabric of the refuge, he had glimpsed recognizable shadows that spoke of a tiny body, shaking and unable to rest as it needed. He had recognized the owner of that body, remembering the little exchange of words with the two portraits of his predecessors, and with that remembrance he couldn't help but reflect how that cursed word – Mudblood – had once again been spoken at a crucial moment of his life and how, this time, he had rejected it with strength, just as he began on the first stage of the final act of his duty and of his atonement: the disclosure to the Boy of his loyalties and of his true self.
His awareness of his own feelings was broken by the words of this present girl, however, because she wasn't speaking of the terrible experience he knew she had endured. Her nightmares weren't a reliving of the Cruciatus curse which she had suffered so many times, nor of the anguish of that never-ending flight through the woods… her worst dream had become something other, he discovered.
"Ah, the blood! All around you… and from your mouth…!" She was sobbing - without violence, but she seemed all the same to be despairing. "The red blood in the vial, the silver memories! You were dying… and it was such a horrible death!" And he felt her horror: he hadn't been consciously aware of how his body had appeared, there in the filthy shack, but now he could almost see it through her frightened words.
She sniffed, ashamed, and suddenly aware: "I know… you are alive, it didn't end like that… but still it seemed so, so real!" He went on caressing her shoulders, unable to answer with adequate words and moved by her sorrow, in which he had sensed something other than fear or repulsion at that sight… and wondering why, among the many deaths of her friends which she had to mourn, the memory of his almost-dead body haunted her nightmares so badly.
But, watching the witch so close to him, he knew that soon the right words would come to him, and that they would be those which his many new accomplishments had made him able to say… and there was all the time in the world for them, to search out the best way to tell her what he knew he had, still, to look for and to live.