of Forever states in "Terra Firma" that the various factions used him to alter his own history and to kill people, so he moved to another planet and went into hiding. The Xindi Braga and Berman created the season-long Xindi story arc, which began with the second-season finale, "The Expanse", and ran throughout the third season until it was resolved in the episode "Zero Hour". It opens with an attack on Earth by a mysterious space probe that kills seven million people in a destructive swath stretching through Florida to Venezuela. As a result, the Enterprise is redirected to unexplored regions of space to find the Xindi and stop a further attack that will destroy Earth. Although certain elements were preplanned, including the success of the mission against the Xindi, others, such as the details of the actual enemy race, were not. At the time of the initial development, Berman and Braga were uncertain if the storyline would last for a whole season or for just half a season. The Xindi themselves were developed from on-set discussions with the writers and the actors who portrayed them. Six species that make up the Xindi were created in this manner. One was originally called "humanoid Xindi", but after further discussions they were renamed "primate Xindi". The first part of the third season saw the crew searching the Delphic Expanse, attempting to find clues that would lead them to the Xindi. In order to complete this mission, they took on additional crew members in the form of Military Assault Command Operations (abbreviated as MACO) soldiers, due to the increased military nature of the task. Founding of the Federation The birth of the Federation was first hinted at during part two of "Shockwave", which opened the second season. When Manny Coto was made showrunner for the fourth season, he decided that the focus of the series should be to link to that event. With this in mind, his intention was for this season to move towards that goal. Judith and Garfield Reeves-Stevens were hired as writers on Enterprise because they wrote the non-canon novel Federation and after it was suggested by producer Mike Sussman. The episodes for the fourth season were intended to lay the framework for the later creation of the Federation. This was something that the cast said that they would have liked to see more of, with Scott Bakula later saying