On their eighty-ninth lifetime, they're finally Harry Potter and Tom Riddle-slash-Lord Voldemort again.

"Ah, bugger," Tom hisses after killing Lily Potter and then laying his eyes on Harry Potter. The memories flow in without so much a hello, how do you do and all he does is lower his wand and pinch the bridge of his nose. He's experienced it so many times it barely bothers him anymore. "Sorry about that." He grimaces at the infant in the crib.

Harry Potter gives him as much of a deadpan stare as a baby could give.

"It's not like I remembered then! She was blocking my view of you." The Dark Lord says almost defensively and Harry rolls his eyes. Harry raises his arms up in the universal baby gesture of 'pick me the fuck up' and now it's Tom rolling his eyes as he does just that.

"I swear to god, Potter, if you vomit or urinate on me I will-"

"James!" A despaired cry comes from downstairs and they both turn their heads to the general direction it came from. Then they turned back to each other and nodded decisively.

"Right, time to go." And not a second after Tom apparates them away does Sirius Black burst into Harry's nursery to see Lily's cooling corpse.

Here's how it starts:

Harry Potter, the first time, lived a very fulfilling and mostly peaceful life. He was an Auror for quite a bit of time, which was alright, but once his precious Lily Luna started Hogwarts he quietly retired that job and flourished as Hogwart's DADA professor. He taught for a good two decades before he and Ginny decided to do a bit of a world tour, and settled back in Britain after five years, just when their third grandchild was born. He then quietly died surrounded by friends and family after proving that yes, dragonpox can kill even an old Harry Potter.

In retrospect, his entire life post-Voldemort was rather… bland.

But when he found himself in the Afterlife King's Cross after taking his last breath, he was rather… confuddled. Then he saw Tom Riddle - looking perfectly human and whole - irritatingly sitting on the only bench and said the first thing that came to mind.

"What the fuc-"

"About time you got here-" Tom had angrily started, before everything became white and the next thing he knew, he was twenty two year old Alexander Baker with the memories of two lives, having just remembered his time as Harry Potter once he laid eyes on nineteen year old William Terrence, who had been apparently Tom Riddle.

"Potter," William- or no, Tom, hisses. "What did you do?"

"What makes you think it was my fault?!" Alexander/Harry says indignantly.

"It's always your fault!"

They staunchly refused to do anything with each other for about four lifetimes after that and honestly could've gone longer if it weren't for a certain intervention.

"Look," A hooded figure in a dark cloak sounded almost exasperated, "both of your souls are tied together, okay? So you're both going to be waiting for each other each time one of you dies, then you both get reincarnated in god-knows when and where, and inevitably you'll both meet again and regain your memories of your past life."

"But why?" Harry asked, and he wasn't whining, really.

It shrugged at him. "Like I said, you're soulmates."

"That's disgusting," Tom flatly said, and Harry was both offended and in agreement.

"Blame it on the Hallows, or Death!" It said. "But really, you," it points at Tom, "are the one that made him your hocrux for more than a decade, and you," it points at Harry, "are the one that became the Master of Death. So technically you both did this to yourselves."

"Bullshi-"

"Oh would you look at the time, bye!"

And it was that damning white light again.

On their eleventh life, they finally decide to be adults about the whole thing and talk. The fact that life number ten had Harry and Tom as father and son, respectively - and wasn't that a bit of a traumatizing experience for both of them - was only one of the breaking points.

By number eighteen they were almost friends (they'd been both girls in an all girls' boarding school, and they ruled that place with an iron fist). On number twenty five they started sleeping with each other during the times the age gap wasn't huge enough to make either of them uncomfortable or sent to jail (on number twenty nine, Harry had let Tom's thirty three year old incarnation take his sixteen year old self's virginity, which got Tom almost shot by his very enraged father). On number twenty, thirty seven, and fifty they were blood siblings (once as orphans, once raised by a single mother working three jobs, and once as part of a big loving family much like the Weasley's). On thirty four, thirty nine, forty two, forty six, fifty eight, fifty nine, sixty three, sixty five, sixty six, seventy one, seventy three, eighty, and eighty four, they were even married (sometimes out of convenience, sometimes out of necessity, but even more times out of, strangely, actual affection - because god knows there's more than a dozen lifetimes when they couldn't even stand the sight of each other, but…).

This seemingly endless loop of rebirth was their new normal. Jumping at different points of time as different people each rebirth, but always, never failing, destined to meet, it was-

Well, it changed people. And quite possibly gave them a perverse sense of humor, because lately they've really enjoyed just fucking with people. Just for the principle of it. (Just living their lives all the time tended to get dull quickly.)

And life eighty-nine? As their originals, Harry Potter and Lord Voldemort? Oh, they were going to milk this for all it's worth.

The Daily Prophet headline on November 1st, 1981 is as follows:

The Dark Lord Dead?

The Potters' Last Act of Courage

And on November 2nd, it was this:

Harry Potter: The Boy Who Lived!

From a private cottage in France, Tom snorted into his tea. Whatever Dumbledore think he's trying to pull, it was bound to be interesting. Harry at least was going to get a kick out of it.

Now, regarding his hocruxes...