In 2370, Commander Benjamin Sisko, Quark, Jake Sisko, and Nog from Deep Space 9 visited the planet as part of a planetary survey mission. During the survey the adults made first contact with and were subsequently captured by First Talak'talan while the children were able to escape to the runabout. Learning of Commander Sisko's plight, and the Dominion's attack on the New Bajor Colony, Starfleet ordered the U.S.S. Odyssey to undertake a rescue mission. While successful, the Odyssey was lost in combat with the Jem'Hadar.

Following their encounter with the alien life-form known as Tchema, the crew of the U.S.S. Enterprise-H traveled to Atan with a group of Vorta survivors that they had rescued from the alien creature. The Enterprise was able to establish a colony on the planet, which was named Atan.

In 2439 the crew of the Starship Enterprise responded to a distress call emanating from Chelu II and encountered their Q guardian, who subjected the crew to testing to see whether they would be fit protectors for the Cheluans. While the Enterprise crew was deemed appropriate, the Enterprise refused the offer and Q, begrudgingly, remained guardian of the world and demanded that Starfleet never return.

On Federation Day 2439, the Starship Enterprise lost contact with DS47 and proceeded to the station to investigate. The station was found adrift with its power systems offline and all personnel aboard the station having been murdered. After away teams from Defiant and Enterprise restored systems aboard the station, both vessels were infected with a virus uploaded from the station to their computers and set a collision course for Idran.

Despite the challenges that they've experienced, Drai V remains one of the most important worlds within the Dominion and has been a member since nearly the beginning of the government. As Drai V oversees cloning operations for the Dominion (with hundreds of cloning centers located on the planet's surface and a large shipyard in orbit producing warships), access to the planet is heavily restricted. Early clones produced on the planet included the Tosk, which were a prey species created for Drai hunts. The Jem'Hadar came later, produced from a modified Tosk genetic profile. In many respects the cloning operations have caused the damage to the world as the Drai, Jem'Hadar, and Tosk frequently engage in simulated conflict for training purposes.

In 2439 the Starship Enterprise was ordered to travel to the planet Drai V to return a renegade Tosk apprehended in the Alpha Quadrant to his people. After a brief standoff, the Tosk was able to escape the Enterprise and crashed a Warp capable shuttle into the surface of Drai V. Despite offering to help, the Enterprise was ordered away by the Dominion under threat of loss of Treaty.

Surveyed by the crew of the Starship Defiant in 2373, in an alternate timeline Gaia IV was colonized by the crew of the Defiant following a temporal displacement that caused the ship to crash on the surface. By the 24th century, Gaia IV's colony has grown to nearly 8,000 people living in scattered settlements. Through the actions of Constable Odo, this timeline was prevented when the Defiant's flight plan was modified to avoid the accident.

The Enterprise escorted representatives of the Federation Department of Temporal Investigations to study Gaia in 2439. During their studies, the Enterprise encountered a quantum duplicate of the U.S.S. Defiant, for whom only a year had past instead of decades. The Enterprise crew were forced to act to preserve the timeline, and Gaia was once again lost.

Further details are classified to Starfleet Level X.

Tracking the Dominion fleet to Sisko-Dax 1171, an investigative away team from the U.S.S. Enterprise-H found a downed Dominion Scout Vessel located on a crystalline structure suspended in the atmosphere of Sisko-Dax 1171. Accessing the scout via runabout, the away team learned that the Dominion ship had been on a pilgrimage to find the progenitor species of the Changelings in an effort to answer the mysteries of the creation of the Founders. While assisting with rescue efforts, the Dominion vessel was attacked by a series of large creatures living in the atmosphere of the Brown Dwarf. The crews of both the Enterprise and a Dominion Reconnaissance Ship soon afterward worked together to recover the crews of both the runabout and the Dominion scout.

During subsequent debriefing and review of the analysis conducted on Sisko-Dax 1171 it was discovered that the Brown Dwarf was actually a life-form the size of a Class T Gas Giant. Further analysis revealed that the life-form had a similar chemical composition as the Changelings themselves, indicating that it may be the first Founder. Identified as being hostile to all life, including to the Dominion, the system was quarantined by the Enterprise before departing back for Federation territory, but not before the Founder Odo named it Indurane, the Bajoran word for ancient.

Resembling an Earth jellyfish, Tchema was a spaceborne life-form that was capable of independent travel through deep space. The creature sustained itself on lush forests that grew within its gut biome, and a series of animals that had also come to live within the life-form. In addition to its ability to sustain itself from its forests, Tchema could transform itself into various forms and manipulate matter and energy.

In addition to its natural sentience, Tchema also experienced emotions including the feelings of pain, anger, joy, and gratitude. The life-form also possessed an affinity for psionic abilities, telepathically communicating with first the Enterprise's Counselor and later Chief Engineer during first contact.

Tchema sought the Enterprise crew's assistance in ridding itself of the Vorta refugees that had lived within it for over a century. After a brief conflict, Enterprise's crew were able to extract the Vorta and transport them to a new world. Tchema, meanwhile, proceeded on peacefully looking for its people.

Cheluan society is matriarchal, with women outnumbering men 2 to 1, leading to polygamous marriages. While the Cheluans share many of the same physical capabilities and tolerances of a Human, their respiratory system is far more complex and features more bronchial lobes than traditional humanoids. This evolutionary advantage allows the Cheluans to process different atmospheres that they may encounter and also affords them a limited ability to tolerate exposure to the vacuum of space. Women are commonly taller than the men on Chelu II and Cheluan skin typically has a pale yellowish hue with a bluish tint to their lips and extremities. The Cheluan species has a complete lack of body hair, but they do have a small brow ridge on their foreheads.

A proud, vain, and focused society, the Drai were first encountered by the Federation in 2369 and are characterized by pale-yellow skin, a cleft upper-palate, and corrugated foreheads. Because of their position, the Founders allow the Drai free reign within Dominion Territory to participate in the Sacred Hunt. Drai technology is supplemented by Dominion equipment, enhancing the deadliness of the species. Drai military uniforms are fitted with advanced defensive and sensing equipment that allow them to thrive in almost any environment or arena. The helmets worn by the Hunters allow the user to penetrate the natural cloaking capabilities of not only the Tosk, but also the Jem'Hadar, and powerful personal deflector generators are positioned on their forearms for added protection from weapons.

Because of the many rewards afforded to them by the Founders, the Drai are faithful servants of the Dominion. The Founders placate the Drai by keeping them comfortable and focused on the Sacred Hunt so that the Drai stay out of Dominion politics and focused on the Dominion's goals.

When encountered, Indurane lived within the upper atmosphere of the planet and wasn't encountered until the Runabout Sol reached a series of large crystalline structures that were floating within the atmosphere. The life-form was incredibly hostile to the crews of both vessels, bordering on malevolent. At times Indurane appeared to play with the crews of the downed vessels, curiously investigating both craft before attacking. At times Indurane appeared to be borderline obsessive in its efforts to kill the away team, almost as if driven by a primal urge.

NOTE: Starfleet Exobiology, Starfleet Medical, and Starfleet Planetary Sciences have reviewed Enterprise's Sensor Logs from the encounter with the Indurane. As the planet Indurane has been designated as a living creature, experts have theorized that the Indurane life-form may be either the offspring of the planet or may serve the same function as immune cells. Additional data is needed to make a conclusion; however, further investigation has been denied.

Originating from Vadia IX, the Q have existed for no less than four billion years of history; however, the existence of the Q may be in constant flux through all potentially existing realities. Because of their near immortality, most of the Q have developed an apathetic attitude towards the universe, believing that they had already experienced everything. Due to their boredom, many Q often acted on their own accord and ingratiated themselves into the affairs of others, as well manipulating the inner workings of the galaxy itself. First contact between the Q and the Federation occurred in 2364, when the crew of the Enterprise-D were put on trial as representatives of humanity. By the mid-24th Century the Q Civil War began due to the influence of the United Federation of Planets upon the Q's otherwise timeless, apathetic, and stable culture. The Q Civil War not only impacted the continuum, but also the Milky Way Galaxy itself as the weapons used caused the supernova of numerous stars. The war was ultimately ended upon the birth of a new Q, restoring the Continuum to the status quo and their first natural birth in recorded history. This tentative peace also had another, unanticipated outcome: the Q themselves started to naturally die.

The planet Chelu II was directly impacted by the events of the Q Civil War, with their planet utterly devastated during the conflict. Because of the damage done by the Q, a member of their species chose to serve as the Cheluan's guardian and protected them from many dangers in their history. In 2439 the crew of the Starship Enterprise encountered this Q, who summarily tested Starfleet to serve as the Cheluan's new guardian. Deeming them worthy, the Enterprise crew refused and were banished by Q.

Deeply respected and even admired by the Hunters, each Tosk takes an Oath of Silence regarding the hunt that prevents them from discussing the Sacred Hunt with anyone else. For a Tosk breaching this oath was one of the most shameful acts that they could commit, only surpassed by seeking protection from another race or being captured and returned to their homeworld alive. Because of the secrecy of the Hunt (and the importance of the Drai in the Dominion hierarchy), civilizations belonging to the Dominion are not permitted to interfere with or support a Tosk during the Hunt for any reason. Should a member world interfere, the Dominion give the Drai free reign to inflict retribution against the interloper.

The crew of the Starship Enterprise first encountered the Tosk during their first mission to investigate a Dominion fleet that passed close to Deep Space 47. A Tosk served as the Chief Medical Officer for Odo's expedition aboard the Dominion Scout Revenant and was instrumental in helping to extract both the crews of the Runabout Sol and the Dominion scout from the clutches of the creature known as Indurane. Later, after the Enterprise returned to the Alpha Quadrant, the crew of the Enterprise found the Tosk was a stowaway aboard the vessel and were ordered to return the life-form to the Drai.

Due to their status within the Dominion, many assumed that the Vorta were the Founders and led the government. Instead, Vorta were the Dominion's administrators, commanders, scientists, and diplomats, operating under the authority of the Founders. In addition, they were the lead explorers within the Dominion and often launched on exploratory missions throughout Dominion and unexplored territories. One such expedition was launched from Kurill Prime on a four-year exploratory mission beginning in 2298. Not long after launching, the Vorta vessel encountered a starbase sized creature traveling through space under its own power. During their investigation, an accident caused the Vorta ship to collide with the life-form and crash into its body structure. Determining the life-form to be habitable, the Vorta sent a distress call and awaited rescue. Unfortunately, help never came for the shipwrecked Vorta and they were forced to establish a colony inside the life-form. As, unlike the Jem'Hadar, both male and female Vorta were in service on the expedition and began to pair off, biologically reproducing in lieu of their common cloning practices.

In 2439 the crew of the Starship Enterprise was telepathically contacted by the life-form, now known to the Vorta as Tchema, which sought the Federation's assistance to rid itself of the Vorta refugees. The Enterprise launched an away team to attempt to negotiate with the Vorta, only for the refugees to attack the landing party. At the same time, a Vorta child attacked Tchema with the intent of making the life-form more compliant with the Vorta's wishes. Stopped by the crew of the Enterprise, the Vorta were relocated to a new world and Tchema was allowed to travel on its way to find a new home for itself.