The Phantom Isles by Stephen Alter
It all began with an very old book titled "The Complete Nercromancer". According to the author, now dead reading certain portions from the book could conjure up the dead. One night, Courtney, Ming, and Orion decide to break into the library, read the passages, then wait to see something happen. Nothing. Or so they think until the librarian Alma Parker, opens the door, figures out something is not right and begins to investigate.
It's not just that books are not where they should be but that certain ones now include moving images when the books are opened. The pages are living, breathing, and talking in a language that no one understands. Somehow the ghosts are trapped inside the pages, with no way to get out. Courtney, Ming, Orion and Alma the librarian are determined to free the ghosts, but first must unravel the mystery of how they were trapped in the first place. Since all the books came from same author they decided that the ghosts were from the professor's strange experiments on an island called Ilas dos Fantasmas.
The best place to start would be with the professor's son only has just died and now is a ghost too...how will he be of any help to them?
Meanwhile the whole town is crazed about what they think may be going on at the library. Time is of the essence, they must hurry if they are to save the ghosts of Ilas dos Fantasmas.