Izuna Uchiha was waiting for Tobirama Senju in the desert.

He knew Tobirama would find him there, as he always found him. He loved this fact about Tobirama, this ability of his, but he suspected it was a heavy burden for him as well.

He heard the rattling of Tobirama's robe as he approached but didn't turn round, only hopped to the side to display he wanted Tobirama to sit down next to him. 

But Tobirama didn't sit down next to Izuna but behind him, pulling him into his embrace by putting his arms around him from behind. When Tobirama hid his nose into Izuna's neck, Izuna could feel he was crying.

I have waited for this moment.

Izuna wasn't saddened that it had arrived. Instead, he was happy that they had gotten an unexpectedly long amount of time together. The number of times they had strolled hand-in-hand, the number of times they had kissed, the number of times they had made love.

The number of times they had fallen in love with one another, over and over.

For the past time, they had also had the pleasure of enjoying the bright sky of day, where the open space around them was as pale as the purest topaz. Izuna liked seeing how pearly Tobirama's skin became in the light.

"Izuna..." Tobirama started, but his voice got caught somewhere between his heart and his mouth. 

"I know", Izuna said. "I figured it out."

Tobirama was quiet in a way that made Izuna understand that he didn't.

"What do you mean?" the white-haired man asked. 

"I won't be needed for a long time, will I? Fire won't be needed until the arrival of humans you've spoken so much about. And that is a long time for now." Tobirama didn't say anything, and Izuna took hold of his hands. He saw Tobirama had painted his nails a lovely red colour. He liked that a lot on him. "And there's your brother... He wants me out of the way, doesn't he?"

"But I don't care what he wants!" Tobirama shouted and stood up. Izuna sat still calmly, looking at Tobirama as he paced back and forth over the sand. The surroundings were dark now, meaning his brother was on the other side of the planet. Tobirama held his hands behind his head and hissed. "What right does he have to let his happiness go before everyone else's? And we're talking about a life!" Tobirama turned to Izuna, tears streaming down his face. Izuna's heart bled for him and for what he was destined to do. "Your life", he whispered.

Izuna stood up, went to his lover, stood on his tip-toes and braided his fingers in the nape of his neck, the white hairs tickling his fingers. 

When he spoke, he spoke to Tobirama's lips.

"Tell me what you're not telling me." Izuna planted soft kisses on Tobirama's lips while talking. Tobirama's lips were trembling. "Tell me what you're holding back."

Tobirama closed his eyes, leaned his forehead against his entire world, which was Izuna.

And he told Izuna what he had been hiding for so long.

"For humanity to exist, there must be a sun and a moon in the sky", he said. "And the sun and the moon are Hashirama and Madara." He grabbed Izuna's face then, looked at him desperately. "If it was only Hashirama's wish... If it was only for the absence of fire in history... But I know that the upcoming of the sun and the moon as heavenly bodies requires me to kill you. It's between us four and the entire human race..."

"Tobirama, my love", Izuna said, the sweetest smile on his face. "The choice is easy. We can't prioritize us four for so many lives. Imagine all the children who wouldn't be born. Imagine all the couples that wouldn't get the chance to love each other like we do. All the laughter and the tears and the pain, that at the end of the day will be worth it." 

Izuna Uchiha reached his hand into his pocket, took out a sharp stone that Tobirama immediately understood had one purpose only.

"Izuna..." he whispered, his voice only a ghost, aghast.

Izuna leaned forwards and kissed him. Tobirama's hand went to the opening of Izuna's robe, up his thigh...

"No..." Izuna said, smiling as he pushed Tobirama away gently. "No, I can't. It will hurt-" And finally, Izuna's voice cracked. "It will hurt too much. Let's just get it done."

Izuna lifted the stone, but Tobirama grabbed his wrist in the air, both of their arms up in a deadly dance.

"No", he said gently. "No, you're fire. You cannot extinguish yourself. It has to be me..." He leaned forwards, placed his lips on Izuna's. "At least let me kiss you."

"I cannot imagine a better way to leave this world", he whispered back. 

They kissed just as a heavy rain started falling from the skies, drenching them. Tobirama's one hand went to Izuna's face, the sensitive skin on his fingertips unable to feel the difference between rain and tears.

His other hand, still holding on to Izuna's wrist above them, slowly lowered the stone. He started trembling, but Izuna helped him, putting the tip of the stone to his heart.

"It's okay", he whispered to his white-haired lover's lip. "It's not for your brother's selfishness. It is for everything."

Izuna had to keep reminding Tobirama over and over why they were doing this, or else Tobirama would falter. Tobirama could distinguish between the blood and the rain even if his eyes were closed, because the rain was cold and Izuna Uchiha's blood was warm.

He sunk down to the ground together with the dead Izuna. 

Tobirama lay down and began to melt.