It was raining in the Sorachi district.

"Sensei," Don had begun quietly. "Do you remember…"

Splinter did, across the years and the miles and the unknown distance that only the soul could cross. It took them days of poring over maps to match his memories to the place. And now, here they were, standing in the rain and staring at a hole in the ground.

In more ways than one, it had been a long journey.

"Where are we going?" Leo had asked, as Don punched coordinates into the teleporter. Raph had gone ahead with Harold to look at the body, but Leo had already seen it in its near-death condition, and was in no rush to look again.

Don didn't answer at first, instead pressing more buttons on the teleporter's control pad. When the machine emitted a quick pair of beeps – some sort of confirmation of success, Leo supposed – Don half-turned to face him.

"I thought about it for a long time," Don murmured. "And then I thought – of course I know where I want to be buried. I want to be buried with my brothers."

Something spun uncomfortably in Leo's head, until he reassured himself that no, of course he was still alive. It took him another moment to understand what Don meant.

"I thought you didn't believe in reincarnation."

"New evidence has forced me to accept the theory," Don replied.

Leo shifted from foot to foot. He had thought he accepted the idea too, but now that he was running up against it in a less abstract form, nothing seemed to make sense. Somehow, contemplating his dead human self was harder than meeting his live human self when Renet had sent them travelling through time.

"Do you really think we're buried there?" he finally settled on asking.

"No."

"But… ?"

Don turned back to the teleporter's control panel, though Leo suspected he was more avoiding the question than doing any real work. "I think we were eaten by scavengers. Who would have buried us?"

It made a dismal kind of sense, and Leo didn't want to think about it anymore. Fortunately, just then Raph called him into the other room, and it was time to go.

Raph carried the body through the teleporter, with Leo.

If he looked closely, he could see the seam on the back of the scalp, where Don had cut his own head open to remove his brain. He had kind of thought Don should mention that, when he caught up the family on the bad news. But he hadn't, and Raph could tell that Leo wasn't noticing anything amiss.

He couldn't decide whether the body was lighter than it should have been, or whether it was only his imagination. How much had Don amputated? How much of their brother were they burying?

What did a soul weigh?

He told himself it wasn't important. What he was carrying was nothing more than meat and bone, nothing more than the blood they spilled in battle and the scutes they shed in spring, scratching and grumbling. All that mattered of Donatello was standing a few yards away, gazing over the rainy mountain range, probably running some esoteric calculations on how old the rocks were.

Don turned towards him, and Raph would have sworn a smile ghosted across his mechanical face.

He grunted at Leo, and they laid the body down on a patch of grass.

Splinter did not recognize the place, when he stepped through the portal onto the rocky slope. How could he? It had been over a hundred years since he had last laid eyes on it. Old trees had died and new ones had grown. Modern towns had sprouted on the flanks of the mountain. And the fires of Tokachi still burned; fresh lava flows had rearranged the terrain.

He could feel his sons' eyes on him as he walked back and forth. Though the details of the landscape were unfamiliar, the spirit of the mountain reached out to him. This was a place he had been, in another lifetime.

He listened to the echoes of the past. There was the cave where he had taken refuge with his sons. There had been the patch of bushes where he gathered berries, all that he could find to soothe his children's growling stomachs. And there was the place where he had pleaded with Saki, and known no more, until suddenly he was looking at the world through the eyes of a rat.

They were in the right place.

He nodded to his sons, and they moved forward to begin the ritual.

Not that Mike really knew how to behave at a funeral, but he certainly didn't know how to behave at a funeral for someone who wasn't dead.

He had helped dig a hole, through mud and gravel and some type of heavy, dark soil. He had helped lower Don's body into the earth, arranging it into a comfortable position. He had listened to Splinter recite the prayers, knowing he was the only one of his brothers who understood the Japanese words. And then he had helped to replace the dirt and rocks and clumps of grass, carefully disguising the grave. The mountain was remote, but the last thing they needed was some hiker stumbling across a half-decomposed mutant and causing an international scientific incident.

When they were done, it looked as though nothing had happened – except, of course, that there was a robot standing where Donatello should have been.

"I can call Harold to bring us back whenever we're ready," the robot with Don's mask said, and then, without quite saying that he wasn't ready, he moved away down the mountain.

Mike went in the opposite direction, because when you found yourself on a mountain in Japan, standing on the summit seemed like the thing to do. There was nothing to see from up there, though; the clouds hung heavy from one horizon to the other.

After a while Mike went back down to find his brother. Don was sitting on a boulder, gazing at the line of mountains that marched timelessly to the end of the world.

"Hey."

Don looked down at him. "Hey."

Mike leaned his shell against the boulder, looking in the opposite direction. "Can I ask you something?"

"Mm?"

Mike hesitated, sensing that something irrevocable might happen if he got an answer. "Are – Are you immortal now?"

Don's reply was surprisingly quick, surprisingly calm. "I think we all are."

Mike hadn't been prepared for that. "Uh?"

"Honeycutt told me once… every time we go through a portal, our bodies are completely destroyed. But our souls come out the other end just fine. And not just us, I mean, everyone…" He paused until Mike looked up at him. "No one can explain it. Not the Neutrinos, not the Utroms, and certainly no one on Earth. But there it is."

"So even if we die," Mike said, feeling his way through this new idea, "we'll still basically be us? Forever?"

"You are my annoying little brother," Don confirmed. "Until the end of time."

"Wow," Mike said. "You get to enjoy my charming presence for all eternity. You are one lucky guy, Robo-bro."

Don seemed to think the nickname was fine, and Mike got the feeling it always would be, from now on.