In dead night, pun intended, Death woke up to see Geno screaming and a small child sitting next to Geno.

"Calm down, it's just me." The child spoke, rubbing her ears in pain. "You scream like a girl."

Geno stuttered a comeback, "Well you're uhhhhh short."

"I'm a child." The child rubbed her temples. "That's why I'm short."

Geno kept quiet for a moment and opened his mouth to say something else offensive but Death cut in, "What are you doing here, stalking my boyfriend."

"I'm not his boyfrie-" Geno mumbled was interrupted by the child's reply.

"Obviously, here to pick up my package."

And the lights were turned on by Papyrus all of a sudden.

"What's going on here?" He asked, as his eyes swept across the room. "Never the mind." Papyrus left with the lights on.

"Core Frisk?" Death narrowed his eyes at the child, the lights hurt his eye-sockets a little.

"Indeed I am Core Frisk and like I was saying. I'm here to pick Geno up." Core Frisk patted their pants and lent her hand to Geno, who was sitting uncomfortably and leaning against the bedside of Death's bed.

Death arched his eyebrow at Geno. Geno seemed to avoid eye-contact. "What? Why?"

"Duh, he promised to stay in the Omega Timeline if he came on his date here with you."

"I don't understand." Death looked at Geno, who was now willing to look at Death in the eye.

Geno huffed out a sigh and explained. "I promised Core Frisk that I'd stay in the Omega Timeline."

Death twirled his sheets on his finger and said, "But you don't need to anymore. You're fine." Geno messed with his scarf in silence.

Core Frisk took charge of explaining.

Basically, two Sanses in one AU messes some stuff up. Since Geno's code didn't really belong in Undertale, he had to stay in the Omega Timeline where other people like him lived. He couldn't leave though, since he's code belonged to nowhere but the void.

"Look, I'll leave in the morning." Geno said, immediately after that he fell flat on his back and fell asleep.