Petunia was washing the dinner plates in the kitchen when she noticed a post owl pecking at the window. She opened the window, reached into a cabinet for the owl treats (she had a fondness for birds of all types), took the thick envelope tied to the owl's leg, and gave it a treat. The Owl hooted an approval, flexed its wings, and flew off into the night. "Wonder what's up with Lilly.." she thought. She talked to he sister on the telephone every few days, so for her to send a post owl was quite irregular.
She sat down and started reading the letter. She then became very angry. "Vernon!" she yelled. Vernon, came running into the kitchen from the living room. With shaking hands, she handed him the letter. After reading it, he turned the same shade of purple that he usually reserved for the worst problems at the office. "What does that freak think he's doing?!" was his only reply.
Petunia got up from the kitchen chair, and asked her husband "Can you watch Dudley for a bit, dear? I have to go out." Vernon was a little confused. "Certainly sweetie, but where are you going?" Her reply turned Vernon's blood cold. "I need to visit my father." was her simple reply.
Severus Snape was furious. One of the Dark Lord's spies overheard a prophecy involving The dark Lord and The Potters' son. Voldemort was planning on killing the infant Harry Potter to avert the prophecy. Snape went straight to Dumbledore, who simply said. "Don't worry Severus. Everything has been taken care of." When pressed for more, Dumbledore just responded with a bunch of generalized platitudes about "The Greater Good." That was the last straw for Snape. "You can ride your 'greater good' to the lowest pits of Hell, Headmaster. I'm done." With that, Severus Snape, potions master and spy for The Order of The Phoenix, disapparated. It would be a long time before he was seen in Hogwarts, or even England, again.
Nikola Tesla looked at the message he received from his fellow veteran, Jonathan Evans. Working for the Paranormal Division of the OSS during World War II, he met Evans who was his liaison for the British SIS. Together the wizards in the OSS and SIS worked with Albus Dumbledore to defeat Gellert Grindelwald, but after the war something in Dumbledore changed.
Tesla remembered that Evan's son-in-law, Vernon Dursey, ran the Sales Engineering department at Grunnings London. Grunnings did a lot of work for the US DMPA, and had a big office and manufacturing plant just North of Boston...