A trip to Egypt. A secret purpose. Something's wrong.
Narcissa Malfoy has been underestimated all her life. It's okay. She likes it better that way.
It's a fun night in eighth year picking plants for Herbology, until Hermione accidentally reveals a few illegal things she did at Hogwarts.
McGonagall finds out about Harry's... living situation. She decides to do something about it. As is her wont, she succeeds.
There's no way none of the Slytherins fought for Hogwarts in the Battle of Hogwarts. They're just too smart to be caught doing so.
After the Battle of Hogwarts, Percy tries to avoid his family. He doesn't really succeed.
Walburga visits Sirius after his release (escape) from Azkaban. They have a little chat.