He auditioned in Los Angeles for Gene Roddenberry's "" with Lisa Howard for Jonas McCord (executive producer and writer), then met Paul Gertz (also executive producer writer). They were both pleased with his performance. He joined the cast in the second season (1998) as Liam Kincaid (a human-Kimera hybrid), replacing Kevin Kilner as the lead actor. This is the role for which he is most famous. After two seasons in the series, Leeshock was comfortable in his role but found playing a lead character exhaustive and a huge responsibility. He was released from the series as a business decision to minimize production costs; television producers pay less tax when they use Canadian actors. He left after the fourth season to return for the series finale in season 5.