It is 1982 and Jennie Samantha Williamson, Marilyn Monroe's nineteen-year-old future daughter, has inherited her mother's addiction to Nembutals. When she discovers the Time Bubble's Golden Key in a table beside her mother's bed, she makes plans to travel back in time to 1971 in an attempt to stop a chain of events that culminated in an undersea disaster. But first, Jennie must travel to September 15, 1954 in New York City, where Marilyn Monroe is filming The Seven Year Itch. After she persuades her mother that she is her future daughter and that time travel is possible, she still must convince Marilyn to travel ahead in time seventeen years to dive once again into Santa Monica Bay, hopefully changing fate in the process. Meanwhile as Marilyn and her future husband travel to 2068 to explore an underground city and search for a time machine's sketches, Jennie knows the secret to stopping the 1971 underwater disaster lies in the palm of her future mother's hand-but only if she can safely transport Marilyn back to 1971 from 2068 before the Sentinels of The System hunt down and kill all three for their defiance.