 The series told the story of the Valorians, a peaceful race of telepathic humans whose home planet was conquered by the Rulon Empire.400 survivors escaped on a space ship and time traveled to prehistoric Earth using the experimental Space-Time Energy Projector (also known as the S.T.E.P).But Emperor Krulos and his lead commanders accidentally followed them into the past when a tractor beam locked onto the Valorians' ship during the time jump.