Disclaimer: I don't own Naruto or any of its characters.
Warning: Spoilers up through Chapter 607 of the manga.
Madara's underground cavern exists in a perpetual state of semidarkness. The only light comes from braziers and candles placed haphazardly around the huge chamber by the half-plant beings called Zetsu. The light is fitful and flickering, casting deep shadows on the damp walls. The cave isn't airtight, and the erratic breezes make the flames leap and dance, so that the shadows seem to move. When this happens, the shadows of the Zetsu-beings that dangle from the Gedo Mazou tree sway back and forth like hanged corpses at the end of a noose. Of course, sometimes the hanging Zetsus actually do move, when they've matured and are about to drop from the tree. (Obito used to like visiting an apple orchard just outside Konoha with Kakashi and Rin, but he doesn't think he'll ever be able to look at a fruit tree the same way again.)
Even Sharingan eyes can play tricks on you in such an environment. Sometimes Obito thinks he sees a small, slim figure disappearing around a corner or a flash of amber eyes peeking out from behind the tree. When he lies in the oversized bed at night, he sometimes sees a vague figure huddled in a corner, watching him. "Zetsu-san?" he whispers, but there's never any answer. When he blinks, the figure is gone.
Once, he asks a Zetsu (the half-black, half-white one) whether there's anyone else in the hideout. "Just us," says Zetsu, "unless you count him." He points to where Hashirama's head and torso protrude from the Gedo Mazou.
"There's no, uh, no girls here, are there?"
Zetsu chuckles. "Growing up fast, aren't you? No, there are no girls here."
Obito understands that Nagato and his followers are important for the eventual success of the Moon's Eye Plan, but he finds their presence grating. Yahiko, in particular, reminds him so much of his former idealistic, naive self that sometimes Obito wants to punch him.
And then there's Konan. She's the quietest of the three, rarely saying much of anything in their meetings. She's also Yahiko and Nagato's staunchest supporter, putting her trust fully in them. In Obito's mind, this makes her an idiot. Don't you know that you can't count on them to protect you? In this world, even the assurances of friends are meaningless. Rin trusted in her friends too, and look where that got her.
It's after one of his meetings with the Amegakure three that he sees her clearly for the first time. The barely audible, stealthy footsteps are what attract his attention first. When he looks up from the scroll he's reading, he sees a couple of the half-formed Zetsu bodies swinging at the ends of their branches, as if someone's just brushed past them. Smoothly drawing a kunai from his weapons pouch, he stalks through the thicket of Zetsu, his Sharingan spinning as he searches for the intruder.
She's standing with her back to the trunk, hands pressed against the unnaturally smooth bark. The animate Zetsu are all off on reconnaissance missions, so they're alone. With his Sharingan active, he knows she isn't just the product of an illusion. At the same time, he can see that her chakra is abnormal in a way he can't articulate. It isn't one of the types of chakra disturbance he's been taught to recognize. Somehow, she's just different.
He's trembling all over, the way you sometimes do when you have a fever. His mouth is suddenly dry, and he has to lick his lips a few times before he can speak. "...Rin?"
She edges away from him as if she's scared, and he reaches out, eager to reassure her. "No, Rin, it's okay! It's me, Obito!" But she darts around the tree, and when he follows, she's nowhere to be seen.
It's almost disturbing how easy it is to dismantle Kirigakure. A word whispered in the right ear, a genjutsu placed on the right person at the right time, is all it takes to ignite the powder keg.
Obito's nails dig into his palms as he watches the fires rage. This is what you get for killing Rin, he thinks. He's been adamant about blaming Mist for her death, because it was obvious that she was their target.
Besides, if he blames them, he doesn't have to blame Kakashi.
"Are you sure you'll be able to do this?" Zetsu asks him before he heads out for Konoha. "You'll have to fight that sensei of yours, you know."
"I know," Obito answers. He can tell that Zetsu has misgivings about this, but Madara left the artificial being with orders to obey him, so he does. For his own part, Obito knows that he'll be perfectly capable of going after Minato with everything he has. After all, Minato is another person he can blame for Rin's death who isn't Kakashi. He should have been there. If he'd been there, those Mist-nin wouldn't have stood a chance, and Kakashi wouldn't have had to do what he did.
When he returns to the cave, he sees her again. He dismisses Zetsu and strides toward her, holding out one hand. She cringes back from him, hiding behind one of the hanging Zetsu-forms. "You don't need to be afraid, Rin," he says, trying to coax her back into view. "I'd never hurt you, you know that."
The branches scrape together and the bodies bump against one another, making a noise like the rustling of leaves. He thinks he can almost make out words in the sound. But you have. It echoes. You have, you have, you have.
The door's been blown off its hinges by an explosive tag, and Obito steps over it to enter the house. His eyes detect some of the traps that the family must have set hastily when they knew an assailant was coming. Other traps, purely mechanical ones that don't contain chakra, aren't as easily seen by the Sharingan, but his intangibility allows him to bypass those too.
Itachi's standing on the stairs to the second floor, holding a girl about his own age in front of him. One arm pins both of hers to her sides, and the other hand holds a kunai at her throat. Her eyes are already dull and glazed: Itachi has apparently gone the sentimental route of using a genjutsu on her so she won't feel it when he kills her. I wonder if Kakashi did the same for Rin.
Itachi draws the kunai across the girl's throat and lets her body drop to the stairs with a thump. Obito suspects that this last part is a show of callousness for his benefit; that if he hadn't come in, Itachi would have lowered the soon-to-be-corpse down gently.
Obito's about to ask whether there's anyone else alive in the house when he sees her. It's the first time he's seen Rin outside the cave, and it takes all his self-control not to react. She's kneeling next to the other dead girl and glaring up reproachfully not at Itachi, but at him.
What does it matter? he thinks. I can just bring her back to life in the dream world. I can bring all of them back, so what's the point of looking so angry?
He often watches Kakashi at the Memorial Stone. The jounin often stays there for hours, relating every detail of the past few days to his "dead" friend. When Obito can't go himself, he sends Zetsu.
"What did he say?" Obito asks.
"He talked about his genin team a little bit. He thinks the Kyuubi kid is a lot like you. He read aloud from the new Icha Icha book. Mostly he apologized."
He sees her moving through the Zetsu army as they stand assembled in the cavern. She shoves them aside as she pushes her way to the front, and none of them seem to notice, perhaps attributing any tactile sensation of her passing to their neighbors. She breaks through the front rank and stares up at him, wringing her hands with a pleading expression on her face. Obito smiles reassuringly at her, trusting that she can see the expression through his mask by either familiarity or supernatural ability. Soon, Rin. Soon I'll bring you back. You don't have to wait much longer, so don't look so worried!
With so many, it takes a while for all of them to move out. While the vanguard is starting on their way, he returns to the tree. Its branches are bare now, like the trees above ground when winter comes. He thinks of ancient mythologies, of stories where a giant tree supports the world and all forms of life are the leaves at the tips of its branches. This world's time is over, he thinks, and the World Tree is dead. But the soil is still fertile, and from it a new tree, a perfect tree, will grow. There will be no more misshapen branches, no more wormy fruit.
She's hiding behind Kakashi, peeking around the side of his body. He seems to be unaware of her slender fingers resting on his arm.
He still doesn't blame Kakashi for her death. He's been very, very careful not to blame Kakashi. But seeing Rin clinging to him, as if hoping that he can protect her from Obito, causes anger to swell up inside him like a wave. What has Kakashi ever done for Rin? Has he killed for her? Started a war for her? Tamed bijuu for her? Is he going to remake the world for her?
"The only thing left to do is to have our final fight," he declares. The only thing left to do is find out which of them loves Rin more.
A/N: The title is from the epigraph to Ray Bradbury's The October Country, way back in the 1950s when it was originally published: "That country whose people are autumn people, thinking only autumn thoughts. Whose people passing at night on the empty walks sound like rain."