After the Enterprise pursued a Borg sphere through a temporal vortex to the year 2063, the vessel's chief engineer, Lieutenant Commander Geordi La Forge, placed Porter in charge of engineering, while La Forge led a team down to Earth to assist Zefram Cochrane in making repairs to his warp ship, which had been damaged in a Borg attack. In that capacity, Porter attempted to correct an apparent malfunction to the ship's environmental controls, by inspecting the EPS conduit in a Jefferies tube adjacent to engineering. While there, he was attacked and assimilated by a Borg drone, one of several who had covertly boarded the Enterprise prior to their ship's destruction.
Following his integration into the Collective, Porter remained in engineering and performed several tasks, including protecting the Borg Queen and aiding in the attempted assimilation of both Lieutenant Commander Data and Captain Jean-Luc Picard. With the death of the Queen, Porter himself died along with his fellow drones. (Star Trek: First Contact)