Disclaimer: I do not own the PowerPuff Girls, sadly. Although, i do own any OC's :D
(Normal P.O.V)
It's been 10 years since Buttercup ran away, leaving the girls - Blossom and Bubbles - heart broken. She ran days after their mother died, obviously couldn't handle the loss of a much loved family member.
The Professor didn't seem as worried. "She'll be back." He always said, he always thought Buttercup would return. Question was, did he want her to? He never looked upset as he passed photo's of her that hung on the wall. Did he really not care? Or did he just hide his suffering?
Losing someone took something away from a person. Not only did he lose Buttercup but he lost his wife - Terri - that was her name. She was the best thing that ever happened to him, but sadly, she was taken away. All to soon. Cancer. That's why she died, that's why she's no longer with them - the Professor, the girls.
But he had to move on, act like everything was okay - but was it really an act? Did he really miss his wife? Who knows. They argued a lot before she died, but as soon as the girls walked in they'd stop, pretend everything was okay.
Their three girls - Blossom, Bubbles and Buttercup - had no idea why they always used to fight. Well, that's a lie, two of them had no idea. But Buttercup knew, she longed for them to stop, but they wouldn't. Well he wouldn't - the Professor - he needed the truth and argued it out of her - of Terri - even though he knew the answer he sort would rip him up inside.
He needed the answer to his question, which only Terri knew, well, and Buttercup. Which is why she hated herself. So when it was time for her to go, she left, without any arguments, without any fights. She packed her bags and left. Did she really want to leave? Or did someone want her to go?