Having just returned from a mission to Mars, Commander Ross isn't exactly himself. He's slowly becoming a terrifying alien entity with one goal -- to procreate with human women! When countless women suffer gruesome deaths after bearing half-alien offspring, scientist Laura Baker and hired assassin Press Lennox use Eve, a more tempered alien clone, to find Ross and his brood. Before long Eve escapes to mate with Ross.
After she delivers her child in an ambulance, alien Eve is killed by a half-breed. Fortunately, Dr. Abbot scoops up the baby alien and escapes. In time, the baby grows into a gorgeous blonde named Sara and begins her quest to find a worthy mate. But Sara is also savage and leaves a trail of deaths in her wake. This carnage makes chemistry student Dean question whether to help her race or not.
Yet to fulfill their rock and roll destiny, the now middle-aged best friends Bill and Ted set out on a new adventure when a visitor from the future warns them that only their song can save life as we know it. Along the way, they are helped by their daughters, a new batch of historical figures and a few music legends—to seek the song that will set their world right and bring harmony to the universe.
