Severus had been thrown into a frenzy after his encounter with Lily and was desperate to come up with a way to win Lily back, make her see that Potter and his arrogant ways were not worthy of her...which is why he was standing in Headmaster Dumbledore's office now.

"Please, sir, it would mean so much to her if her sister could..."

"I am sorry, Mr. Snape. I cannot bestow the gift of magic on one who does not have magical blood. Ms. Evans understands this, you should as well."

Severus bit his lip and looked at the ground.