(coexisting on another dimensional plane)
The ISS Avenger (NX-09) was a Terran NX-class battle cruiser that was in service to Starfleet in the mid-22nd century. Avenger had fought for the Terran Empire in their war against rebels in the 2150s, and was one of several vessels destroyed by the starship USS Defiant during Jonathan Archer's power struggle for the throne of the Empire.
On January 18, Avenger was caught in an attack by rebels and suffered heavy damage and casualties, including the death of her captain, but was saved by the intervention of Jonathan Archer commanding the Defiant. In a plan devised by Archer, Admiral Black was executed and all alien crew members, except for Phlox, were transferred to Avenger. When Phlox sabotaged the Defiant with assistance from Soval, Avenger opened fire on the Defiant. When the sabotage was discovered, Commander Tucker stopped Phlox and reactivated the ship's systems. The Defiant targeted Avenger and destroyed it with all alien hands on board. (ENT: "In a Mirror, Darkly, Part II")
|NX prototypes: NX-Alpha • NX-Beta • NX-Delta|
|Ships: Enterprise NX-01 • Columbia NX-02 • NX-03 • NX-04|
|Mirror universe: ISS Enterprise NX-01 • ISS Avenger NX-09|
According to "In a Mirror, Darkly, Part II" writer Mike Sussman, the name of the ISS Avenger was a homage to the Star Destroyer Avenger, the only Imperial warship given a name within the films themselves, from Star Wars Episode V: The Empire Strikes Back. (Information provided by Mike Sussman)
Audentes Fortuna Imperii, the Latin text on the Avenger's assignment patch, translates to "The Bold [are] the Fortune of the Empire". The intended translation may have been "The Empire is Bold [and] Fortunate", which would have been Imperium [autem] Audet [et] Fortunati. It is based on Audentes Fortuna Juvat ("Fortune favors the bold"), the motto of the Columbia NX-02 in the prime universe, switching just one word.
The registry number "NX-09" implies that the Empire had built at least nine NX-class vessels by that time.
The Avenger NX-09 was also seen in the Star Trek: Legacy computer game as the name of one of the NX-class ships.