Visual effect supervisors Gary Hutzel and Glenn Neufeld were busy completing post-production work on the opening episode of the fourth season, "". In their place, visual effects coordinator David Takemura led on the visual effects work on both "Rejoined" and "". For this episode, his two main tasks were the creation of the artificial wormhole and the sequence where Dax uses a forcefield as a walkway to reach a trapped Kahn. Takemura was relieved that the wormhole was intended to be artificial in nature, as it meant that he did not have to attempt to re-create the detail already seen in the Bajoran wormhole on the series. Once he came up with the basic design, visual effects company VisionArt completed it.