Frankie Elkin is an expert at finding the missing persons that the rest of the world has forgotten, but even she couldn’t have anticipated this latest request—to locate the long-lost sister of a female serial killer facing execution in three weeks’ time.

#1 NYT bestselling author Lisa Gardner gives us the inside scoop and takes your questions live. You won't want to miss this event with the author the Associated Press deems, “a master of the psychological thriller.”