Edghill, Rosemary. The Cup of Morning Shadows (New York: Daw Books, 1995) 317 p.

In this second book of the Twelve Treasures series Ruth Marlowe has her library degree and a job at the Ryerson Memorial Library in Ippisiqua, New York. She and the mysterious Library Director Nicodemus Brightlaw fall through a magical bookcase in the library basement and find themselves in the land of the elves. They later meet Philip LeStrange, one of the library students from the first book. It turns out Philip has been living in the elf world having fallen through the same bookcase.