Over our Heads - Serie "The Valens Legacy", Vol. 3, di Jan Stryvant

Sean's still up to his neck in trouble, but at least he's finally found an example of his father's work, along with all of his notes. Now all Sean has to do is figure out not only how to reproduce his father's greatest achievement, but to solve the one problem his father wasn't able to. Holed up in a cold war era bomb shelter, all Sean wants to do now is keep his head down and his family safe, while he untangles this latest problem.
Like it or not however, Sean has set events in motion that will change the future for all of the mages and supernatural beings involved, should he prove successful. While many may welcome these changes and the freedom it will bring them, some of the more powerful councils will most definitely not.