You are the adopted daughter of Toriel and Asgore, and since the death of Chara and Asriel, you have been the only thing that has kept them together, no wonder they treated you with extreme care and protection. Today was in fact your birthday, you had finally come of age, and your parents had prepared a big party for you. As soon as you entered the throne room you were flooded with hugs and presents, all your friends and many, if not all the monsters of the Underground were there to celebrate your birthday. Everything was perfect, until a loud noise caught everyone's attention. Someone had just smashed through a glass window to enter the room, they were a group of five skeletons who looked a lot like Sans.

“It seems like someone forgot to give us an invitation.”

Killer said with a smirk on his face, followed later by Horror.

“Yeah, let's hope we're not late for the cake.”

He laughed, moving to the side and letting their leader, Nightmare, pass ahead.

“So much joy...it's disgusting.”

He said as his gaze shifted to you, taking a few steps toward you.

“Here's the birthday girl/boy”

Nightmare mumbled, and before Asgore could get in front to block him from approaching you, Error grabbed him with his strings, holding him in place.