The premise of John Birminghamsnew thriller is simple: What if America disappeared? If it just fell off the face of the earth? In Without Warning, Birmingham, whos written several other novels with equally foreboding titles such as Final Impact and Designated Targets, gives readers a world sans its only superpower. With no one on guard duty, violence breaks out and stock markets go into free fall. As chaos and corruption take over, the question isnt so much whether anyone can save the world as, can anyone survive it? The reading/signing starts at 7 p.m. Borders Books - Kirby, 3025 Kirby. For information, call 713-524-0200 or visit www.borders.com. Free.