Iden Versio was a human female soldier who served in the military of the Galactic Empire. A TIE fighter pilot in the Imperial Starfighter Corps, Iden became Commander of Inferno Squad, an Imperial Special Forces commando unit assembled by her father, Admiral Garrick Versio, in response to the destruction of the Death Star. Along with Agents Gideon Hask, Del Meeko, and Seyn Marana, she infiltrated the Dreamers and successfully destroyed them, though Marana died in the mission. Inferno Squad would later go on to participate in and conduct special operations for the Empire in the Galactic Civil War, and participated in the Battle of Endor, which saw the death of Emperor Palpatine and the destruction of the second Death Star, resulting in the fracturing of the Empire with the lack of a line of succession and broken chain of command. In the immediate aftermath of the battle, the secret Contingency was activated, and Messenger droids carried the final posthumous orders of the Emperor to select Imperial officers, among them Admiral Versio: Operation: Cinder was to begin at once. However, when climate disruption arrays targeted the Versio homeworld of Vardos as part of Operation: Cinder, Iden and Meeko both went rogue, escaping aboard the Corvus and surrendering to the Rebel Alliance. Iden and Meeko both agreed to help the Rebellion combat Operation: Cinder at the Battle of Theed, and ultimately decided to defect to the Rebellion and join the New Republic.
Retaining her rank of Commander of Inferno Squad, Iden fought against the Imperial remnants throughout the final year of the Galactic Civil War, making attempts to capture Hask and her father. Inferno fought at the Battle of Jakku, where Iden and Shriv Suurgav answered several distress calls and fought against Hask, who was shot down by Iden. She later attempted to save her father aboard the Eviscerator, but her father declined her rescue attempt, choosing to go down with his ship, though made peace with Iden in his final moments. Iden fled in an escape pod, crash landing on Jakku and reuniting with Del and Shriv.
Iden and Del went on to marry and had a daughter named Zay Versio. Twenty-nine years after the Battle of Jakku, Del went missing, and Iden, accompanied by Shriv and Zay, went in search of him. This led them back to Vardos, where they were met by Hask, who had survived the Battle of Jakku and become an officer of the First Order. He revealed to her that he had killed Del; and during a skirmish aboard his Resurgent-class Star Destroyer Retribution, during which they stole schematics for the First Order Dreadnought, he attempted to kill Zay as well, but Iden killed him first. Before his death, however, he managed to fatally wound her. Iden died in her daughter's arms as the Retribution came out of hyperspace into the Battle of Starkiller Base. Zay and Shriv went on to deliver the plans for the First Order dreadnought to the Resistance, whereupon Poe Dameron used them to take down the Fulminatrix during the evacuation of D'Qar.