Four children travel through Christian`s grandfather Ronson`s tower and with blue light that develops at a thunderstorm over 1,000 years to the past. They discover the supposed-sunken city Magna Aura and meet there Drago who looks similar like Christian`s grandfather, his brother Morton who rules Magna Aura, and three children who become their friends. In the present, Ronson, his son-in-law Alexander, Elena, the mother of one time-travel kid, and two other children try to get back the kids.