A. G. Harrison 
Feel The Movement [EPUB ebook] 

They ran as fast as they could out of the ballroom down the hallway. Glass was falling from the skylight in the main foyer blocking the main entrance. Crystal held out the dagger which started to glow bright silver, the shards of glass stopped falling freezing in mid air. The glass parted making a pathway as they raced across the foyer. Once on the other side all the glass fell to the ground.