Phineas Nigellus and the Half Blood Prince
"I've dropped my plans to poison my wife – she's punished enough by morning sickness," Phineas thought absentmindedly, caressing his gloves. Next moment the would-be victim was running to bathroom but she never made it. Distastefully displayed bits of breakfast ended on his brand-new silky piece of clothing and he was, in language of today, totally pissed off. And we all know, it's bad if Headmaster Nigellus gets only slightly irritated early in the morning. All the Hogwarts actually suffers the consequences. When Phineas arrived at work (not just slightly irritated) the first person/thing he met was the devilish poltergeist. With a just too polite bow Peeves asked: "Lovely morning, your Headmastership! Did your wife mistake you for vomit bucket again?"
Poltergeist was too bright to wait for the response, but Phineas didn't really care. How unusual for him! Even Blacks look at the bright side of live sometimes and even such mockery was worth for getting the new Black family name bearer, the pure blood princess.
To be continued as soon as the official title of book 7 is made known!