Complex sentence: In the 1965-66 season, he appeared on "F Troop", but left to star in a new series; in 1966, he would co-star with James Darren in the science fiction time-travel television series "Time Tunnel".
Split into simpler sentences: In the 1965-66 season, he appeared on "F Troop", but left to star in a new series. In 1966, he would co-star with James Darren in the science fiction time-travel television series "Time Tunnel".