A local writer will be downtown today signing copies of her new book.Author Christal Arthur will be at Coffee Corner this morning from 9 to 11 signing copies of her new book Overdrawn. She explains her decision to write a book came while she was taking a class at the University of Iowa Writers Workshop. Arthur says her past writing has been mostly technical work submitted to journals. Arthur describes the book as a mystery that deals with relationships at home and at work, and themes that include moral decision making.