Help! I'm a Prisoner in the Library by Eth Clifford

Mary Rose's father always waits until the last minute to do everything. Now they're in the middle of a blizzard and the car runs out of gas. Mary Rose and her younger sister Jo-Beth are supposed to wait in the car until he comes back. But Jo-Beth is just like their father. She has to go to the bathroom. Immediately! Where--at 5:00 p.m. on a Saturday night--in a blizzard can Jo-Beth find a restroom? Mary Rose discovers a library and they dash inside just before it closes. But the two girls are so fascinated with all the different displays that the librarian locks up, turns out the lights and leaves without even seeing them. Mary Rose and Jo-Beth are trapped! No one knows where they are. Suddenly, with the lights out, the library is no longer fascinating. It's strange and creepy and now they are prisoners! Then the hear noises. Who is locked in there with them? Is this place haunted? What kind of library IS this anyway?