Johnny Mysto: Boy Wizard tells the story of an amateur magician who discovers new and mystical powers. After receiving a ring, Johnny (Toran Caudell) discovers he has new powers of illusion. While practicing his tricks and wearing his new ring, Mysto accidentally transports his sister, Andrea (Sarah Haseltine), back through time into the ancient kingdom of Camelot. Johnny, then, must travel back to rescue his sister from the evil Malfeasor (Michael Ansara) who has conquered King Arthur's realm. He gets there with the help of television illusionist, The Great Blackmoor (Russ Tamblyn), who mentors the young magician, showing him how to travel back in time. Along the way, Johnny learns his ring actually once belonged to renowned wizard Merlin (Ian Abercrombie). He helps Johnny and his friend Blackmoor make their way through the kingdom looking for Andrea and use magic to evade and defeat those who stand in their way. If Johnny can defeat Malfeasor and find his sister, he can return to his time and bring Arthur back to his throne.moreless