Bookcase Door to Hidden Room

We’ve all seen it in the movies: you pull the book from the shelf and the mysterious door opens into a secret room to the side.Well, this isn’t a mansion in a murder mystery - just someone’s house - but when they were renovating they wanted maximum book storage but to get it they had to obstruct a door. Instead of an ungainly workaround they simple bookcased over the door and made a secret one