It's possible you might be thinking of one of these titles:
* "I Know What You Did Last Summer" (1973): This is Lois Duncan's most famous novel, a suspenseful story about four teenagers who are terrorized after a hit-and-run accident. The book's plot revolves around a mysterious figure who is obsessed with the teens and their secrets.
* "The Twisted Window" (1995): This book is by Carolyn Keene, the author of the Nancy Drew series. It's a mystery story featuring Nancy Drew.
To find the book you're looking for, you might try:
* Checking the author's bibliography: You can find a list of Lois Duncan's published works on websites like Goodreads or Wikipedia.
* Using a search engine: Search for "The Twisted Window Lois Duncan" to see if there's any information about a book by that name.
* Checking your local library or bookstore: They might have a copy of the book you're looking for or be able to help you find it.
If you provide more details about the book (e.g., the genre, a brief summary, etc.), it might be easier to help you identify it.