In 2439 the Starship Enterprise was ordered to travel to the planet Drai to return a renegade Tosk apprehended in the Alpha Quadrant.

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. Acessing 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 not a Brown Dwarf but was rather 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.

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.

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.