In 2439 the crew of the Starship Enterprise responded to a distress call emanating from Chelu II and encountered their 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 remained guardian of the world.

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

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.

Upon investigation an away team from the Enterprise located a downed Dominion Scout Vessel located on a crystalline structure suspended in the atmosphere of Sisko-Dax 1171. Accessing the scout, the away team learned that the Dominion ship had been on a pilgrimage to find the progenitor species of the Changelings to help answer the mysteries of the Dominion. While assisting with rescue efforts the away team discovered that Sisko-Dax 1171 was one huge life-form that had a similar chemical makeup as the Changelings themselves. Hostile to all life, the planet 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.

While the Cheluans share many of the same physical capabilities and tolerances of a Human, their respiratory system is far more complex and feature more bronchial lobes than traditional humanoids. This evolutionary advantage allows the Cheluans to process different atmospheres that they may encounter, and a limited ability to tolerate exposure to vacuum. Typically, a Cheulan skin has a pale yellowish hue with a bluish tint to their lips and extremities with a small brow ridge and a lack of body hair. Cheluan society is matriarchal, with women outnumbering men and commonly being taller.

Focused upon the hunt, Drai technology is designed with a tactical mindset. Drai military uniforms can shield the hunter from many weapons and incorporate sophisticated sensor technology to aid in the hunt. The Drai are awarded significant freedom in the Dominion due to their advanced cloning capabilities, producing not only the Tosk but also the Jem'Hadar for the Dominion. Faithful servants of the Dominion, the Drai are comfortable focusing on their own aims and rarely engage in politics with the Dominion and its members.

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 the offspring of the planet or may serve the same function as immune cells. Further data is needed to make a conclusion.

As demonstrated during encounters with the Q, their capabilities can reach cosmic levels of power. With a mere thought, and a snap of their fingers or a wave of their hand, the Q have displayed unlimited control over space, time, and matter. Despite this, if a Q neglected to use their powers for a long time, their abilities could become limited or lead to undesirable outcomes. The Q themselves live in a highly ordered society, though some argue it was also a virtually stagnant one, which led to a Civil War within the Q Continuum that existed with flashpoints at several key moments throughout history that devastated subspace and many worlds. A tentative peace was established with the birth of the first Q child; however, the damage had already been done and the Q themselves started to die for the first time in their history.

Tosk was initially encountered by the Enterprise crew when the alien served as Chief Medical Officer for Odo's expedition to find the Changeling now known as Indurane. Initially believed to have returned with Odo, instead Tosk managed to stowaway aboard the Enterprise where he was later detected.