Here is the description on the back of the book:
"It was after hours. Kathleen was preparing to close the library when somebody returned five grisly books about death. One was slashed. All were overdue. Then Kathleen found the bookmark with the deadly warning. Now people close to her are falling victim to tragic accidents. Someone is out for blood. Is it Robin, silent, shy, withdrawn? Is it Alexander, the dark, handsome stranger who haunts the library stacks and says he wants to help? Kathleen can count on only one thing: the killer WILL strike again--her death is overdue...."
Kathleen is working at the creepy old library in town during spring break while the librarian, Miss Finch, attends a seminar. Working with Kathleen is her good friend Robin, a shy, mute young man who always listens to what Kathleen has to say. Then one night someone drops off several long overdue books on murders and torture, with pictures cut out of them, and Kathleen begins to feel uneasy when she finds a bookmark in one of them that reads, "Horrors Await You. Beware." Soon Kathleen's friends begin to get fatally injured, and at every accident site, she finds a book that has to do with the way her friends are being hurt. Who is doing this? Is it Alexander, a college guy who has started hanging around the library? Is it Bran, Kathleen's hot lifelong best friend? Or is it Robin, silent and withdrawn?
The ending was really great, and I never guessed who the killer was. I'm so glad I read this; I almost didn't, because I thought the title was pretty stupid, but I was wrong! Definitely worth anyone's money!