The Sphere-Builders were an alien race from a trans-dimensional realm, who attempted to manipulate the Xindi into destroying Earth. No proper name was ever given for any Sphere-Builder.
Presage []
The Sphere-Builder Presage
This presage was consulted by the other Sphere-Builders on multiple occasions to examine alternate timelines and to gain insight on how the future would be affected by events occurring in the present. She advised the other Sphere-Builders that, due to the actions of the crew of Enterprise NX-01, the possibility of their success was quickly diminishing, leading them to take a more direct hand in attempting to destroy Enterprise. (ENT: "The Council", "Countdown", "Zero Hour")
The Sphere-Builder Presage was played by Mary Mara.
The final draft script of "The Council" described the Sphere-Builder Presage as the individual Sphere-Builder who was "responsible for reading the timelines."
Primary[]
The Sphere-Builder Primary
This primary coordinated the effort to assist the Xindi-Reptilians in deploying the Xindi weapon against Earth so her species could invade the galaxy unopposed in the future. The Sphere-Builder Primary, along with others of her species who boarded Enterprise and attempted to destroy it, was forced back into her own realm when the reconfigured space began to collapse. (ENT: "The Council", "Countdown", "Zero Hour")
The Sphere-Builder Primary was played by Ruth Williamson.
In the final draft script of "The Council", the Sphere-Builder Primary was described as "the Sphere-Builder Woman's superior."
Saboteur[]
A Sphere-Builder
This saboteur was one of nine who transported aboard Enterprise in 2154 to damage the ship's systems and to prevent the Enterprise crew from destroying Sphere 41. When Enterprise was able to destroy the sphere, she de-materialized. (ENT: "Zero Hour")
This Sphere-Builder was portrayed by stunt actress Alina Andrei, who received no credit for her appearance.
In a deleted scene from "Zero Hour", she was electrocuted when she tried to disable the ship's systems.
Test subject []
A test subject found by Enterprise
This test subject was sent as an experiment to determine if reconfigured space in the Delphic Expanse was able to sustain his species.
Enterprise retrieved his transport pod from inside a trans-dimensional disturbance. After being taken to sickbay, the alien claimed that he was a prisoner who was forced to volunteer for the experiment. Captain Archer refused to let him return to his ship, and when Phlox was distracted in sickbay, the alien attacked him and escaped by moving through the ship. After he was recaptured by Lieutenant Reed and Major Hayes, the alien warned Archer that when the Xindi destroyed Earth, his people would take over the prime universe, before disintegrating due to his incompatibility with normal space. (ENT: "Harbinger")
The test subject was played by Star Trek regular Thomas Kopache.
In the final draft script of "Harbinger", this alien character was described thus; "Its hairless, almost fetal-smooth exterior is marred by evidence of physical decay: strange patches of micro-fissures criss-cross his skin."
The fact that the character had a hidden agenda influenced Thomas Kopache's portrayal of the alien. "We had to make sure that the audience wasn't tipped off about that," stated Director David Livingston. "So his performance had to be shaded." ("Enterprise Moments - Season 3", ENT Season 3 DVD special features) The test subject was also depicted with use of a dummy whose abdomen, through use of a tube, could be made to breathe. ("Behind the Camera: Marvin Rush", ENT Season 3 DVD special features)
Woman []
A Sphere-Builder "woman" in 2154
This woman was the primary contact with the Xindi. She appeared to Commander Dolim, urging the Reptilians to press their attack on Earth by deploying the weapon. The Builders promised the Reptilians that they would rule as the dominant species of a new Xindi empire if they hijacked the weapon and attacked Earth without authorization from the Xindi Council. (ENT: "Damage", "The Council", "Countdown", "Zero Hour")
The Sphere-Builder Woman was played by Josette Di Carlo.
In the final draft script of "Damage", the Sphere-Builder Woman was described with the statement, "It's she who's been counseling the Xindi regarding the future."