This has the markings of a great story line.
You are called to investigate the murder of a wizard-in-training. There are the usual signs and smell of *Insert McNasty Here* all over the place. The girl is lying on the floor with a broken neck and bloody stump where her left hand used to be. But why attack a wizard-in-training? Neither her nor her master have any connection to *Insert McNasty Here*. So you do some digging.
Turns out the girl was super smart and at the head of her class. Had a bright future at M.I.T. where she would introduce the world to the next future computing master piece. The Wham!, big league magic power starts waking up inside of her and every computer crashing around her. She hated her new life of retro/basic belongings. Every night she dreamed of silicon chips and overclocked hardware. She would do anything to get her old life back.
Two weeks ago while moping around her Master’s dusty bookstore; she came across a not-so-old book along a back row of shelves. After reading only a few pages she began to light up again and begged her master to allow her to take the book home. Her master is just happy to see a smile on her face and lets her take the book. After all, there was nothing in Mr. Tesla’s book that she could hurt herself with.
That was last time her master saw her alive. After missing two lessons the old man had tried dowsing for her with no luck. It was only after hiring a private investigator (Or one of the PC’s) that he was able to find her hiding spot, and by then she was already dead. A look around the place and you can find a copy of Mr. Nikola Tesla’s “A Guide to Staying Current” (pun intended) lying on a work bench. It’s opened to a chapter describing how one would go about making a “Magical Lightning Rod” capable of suppressing all mortal magic within an area. After talking with a few of her techie friends you can learn that she has begun going back to school and pulling her computer equipment back out of storage. They also note that she never takes her new, weird steampunk watch off.
So there you have it. Girl builds a magical lightning rod. Word gets around. Bad guy finds out. Bad guys kills girl. Bad guy takes a device designed to nullify all mortal magic, no matter the source. Bad things happen….