The Girl From Tomorrow & Tomorrow's End

In the year 3000 the human race is in a state of Utopia. The major challenge facing them is continuing rebuilding the Earth after The Great Disaster, a catastrophic event that took place in 2500 and nearly destroyed the entire Earth. In order to investigate its causes, a scientist named Tulista is sent to the past using the Time Capsule, a device created by a scientist named Bruno. Upon the capsule's return, Tulista is held hostage by Silverthorn, a criminal from the year 2500, who is intent on conquering the future. Realizing that even though the year 3000 does not have weapons per se, his own weapons are no match to the superior technology of the Transducer, he manages to take Alana, Tulista's student, hostage, and escapes into the past, where he figures he will have a better chance. Arriving in 1990 Alana escapes, and later meets a teenager named Jenny Kelly, whose help she enlists in order to get back to the Capsule before it returns to the future, leaving her stranded in the past. After thinking that the Capsule was destroyed, Jenny and Alana discover that it has been seized by Silverthorn, who is building his power in the year 1992 using information from the Capsule's database, and will therefore not allow Alana to use it to return to her own time. Alana and Jenny must devise a plan to retrieve the Capsule while foiling Silverthorn's plans, so that Alana can return home. For that they also enlist the help of Jenny's family and her teacher.