Lost in the Devil's Triangle, trapped in a dimension with beings from the future and from other worlds, a party of adventurers journeys through zones of time back to their own time. Varian, a man from the 23rd century, possessing awesome powers. From 1977, Fred, a young doctor just out of medical school. Scott Jordan, the 13-year-old son of a famous scientist. Liana, daughter of an Atlantean father and an extraterrestrial mother. And Jonathan Willaway, rebel scientist from the 1960s. Together they face the frightening unknown on...the fantastic journey.
Varian (Jared Martin): "A man from the 23rd century possessing awesome powers", Varian generally uses a kind of crystalline "tuning fork" device called the Sonic Energizer through which he focuses his thoughts into what is described as a sonic manipulation of matter. The device is completely useless in anyone else's hands, and seems capable of a huge variety of tasks, from opening doors to disrupting electrical systems to large scale acts of destruction, as well as its apparently intended function as a diagnostic and healing device. Following the departure of Professor Paul Jordan at the end of the pilot film, Varian takes over as de facto leader to the travelers and adopts a parental role over Paul's teenage son, Scott (most notable in episodes such as "An Act of Love" and "Turnabout").
Scott Jordan (Ike Eisenmann): "The 13-year-old son of a famous scientist", Scott has an excellent knowledge of Earth history and events, but is still young and has much to learn.
Dr. Fred Walters (Carl Franklin): "A young doctor just out of medical school" whose impulsive and rather hot-headed nature acts as a counterpoint to the calm, pacifistic Varian. A friend of Scott's father and the only other member of the group from the same time period, the athletic black physician takes the role of protective "older brother" with the young teen.
Liana (Katie Saylor): "Daughter of an Atlantean father and an extraterrestrial mother", the beautiful blond Liana possessed greater than human physical strength (due to her mother being from a higher gravity planet than Earth) and powerful psychic abilities (presumably due to her mixed heritage) which allow her to, among other things, telepathically communicate with animals. Saylor left the show after the episode "Turnabout" due to illness. In the next episode "Riddles" the reason for her not being present with the group was given that she opted to stay a few days at Coriel to help the inhabitants work out their new government and would catch up with the group later.
Dr. Jonathan Willoway (Roddy McDowall): "Rebel scientist from the 1960s" who has a mastery of computers, robotics and scientific knowledge which is quite useful to the group. He is something of a never entirely trustworthy black sheep, basically a cooler version of Dr. Smith from Lost in Space without the congenital cowardice who often tends to do things for his own mysterious reasons. Over the course of the episodes, however, the black-clad Willoway comes to care about Scott and his fellow travelers and becomes more integrated into the group, although Fred makes no secret about still not trusting him which leads to a bickering Spock/McCoy-style relationship between the two.
Sil-El (The Felix Team): Liana's companion and pet, a "tuxedo cat" with which she can communicate telepathically and who sometimes scouts ahead for her, acting as an extra set of eyes and ears.