Isabel Stenzel Byrnes and Anabel Stenzel -- Twin sisters, co-authors of The Power of Two: A Twin Triumph over Cystic Fibrosis, host a book signing and tell about their struggles with cystic fibrosis and their efforts to pursue normal lives while grappling with the knowledge they will die young. / 7 p.m. / Barnes & Noble at the Power Plant, 601 E. Pratt St. / 410-385-1709.
Joann Harris -- A local author who became fascinated with horror stories after reading a Stephen King book appears for a discussion and book signing. Her first novel, Fear of the Beast, begins in a small town in Nebraska, home to a portal that leads directly to hell. / 1 p.m.-3 p.m. / Greetings & Readings, 118 Shawan Road, Hunt Valley / 410-771-3022.
Gregory Curtis -- Author delivers a lecture and signs his book The Cave Painters, which includes photographs taken of paintings found in caves in France and Spain that are more than 30,000 years old. Curtis is also the author of Disarmed: The Story of the Venus de Milo and was the editor of Texas Monthly from 1981 to 2000. / 2 p.m. / Walters Art Museum, Graham Auditorium, 600 N. Charles St. / Free, pre-registration suggested.