casting Donald Petrie was originally signed to direct the episode, but dropped out to direct the film Mystic Pizza. Executive producer Robert Justman brought in Rob Bowman to direct his first Star Trek episode. Justman later said that this was one of his most significant achievements on The Next Generation. Bowman worked on storyboards and set blocking for 20 days before shooting the episode. He was initially nervous about working on the show, and felt he had to prove himself because of his relative inexperience as a director. Bowman said that after the second day of filming, it became easier, and credited the crew with making him feel welcome. He went on to direct twelve more episodes of The Next Generation. Eric Menyuk was cast as the Traveler. The actor had previously been runner-up for the role of Data several weeks earlier (the role went to Brent Spiner). He was a Star Trek fan since age six, and would later return as the Traveler twice more: in "Remember Me" and "Journey's End". Menyuk's return in "Journey's End" would also mark the last on-screen appearance of Wesley Crusher. Biff Yeager made his Next Generation debut in "Where No One Has Gone Before" as Chief Engineer Argyle, who would become the most frequently appearing chief engineer of the first season (appearing twice). Geordi La Forge took over that role in the first episode of season two, "The Child". Stuntman "Dangerous" Dennis Madalone also made his series debut as the science division crewman threatened by his own (imagined) fire. From season three onwards he was stunt coordinator for The Next Generation, and continued to portray a number of crew members. Viewers learned Picard's mother's first name in "Chain of Command"; she was played in "Where No One Has Gone Before" by Herta Ware, who appeared in the 1985 science-fiction film Cocoon. Visual effects and makeup Some effects in the episode were created in Robert Legato's basement with water reflections and Christmas tree lights. The script was vague about what was seen at the end of the universe, so Legato played with the effects of water reflections on his basement wall. Shooting through BoPET film, he created multiple images that were layered over one another for the final effect (which Legato described as "peculiar and bizarre"). Christmas tree lights were suspended and moved, to create the blinking effect seen on screen. The Klingon Targ