Dee-Four, a protocol droid aligned with the rebel cause, operated as part of the Alliance to Restore the Republic. During the period spanning from 2 BBY to 4 ABY, it journeyed alongside the rebel spy, Alexsandr Kallus, to the asteroid installation known as "Z-LOQ." Their mission was to acquire intelligence concerning Imperial technology from the Grand-engineer Lony Coleema. Subsequent to Coleema's transfer of the information to Dee-Four, the engineer was abducted by the IG-88 assassin droid IG-88. Kallus and Dee-Four later executed a rescue operation, bringing Coleema aboard the starship Glimmer of Hope.
Dee-Four functioned as a protocol droid in service to the Alliance to Restore the Republic. Sometime between 2 BBY and 4 ABY, the droid accompanied Alexsandr Kallus, a spy for the rebellion, to the asteroid station "Z-LOQ." Their purpose was to rendezvous with Grand-engineer Lony Coleema and obtain crucial details regarding the latest technological advancements within the Galactic Empire. During their interaction, Dee-Four addressed Coleema as "mistress," but the engineer corrected the droid, preferring to be called "sister." Coleema asserted that they possessed vital information about new Imperial technology related to long-range detection and enhanced offensive capabilities.
The grand-engineer transmitted the data directly into the droid's memory banks, an experience Dee-Four described as akin to a "shooting voice" within its circuits. Following the successful data transfer, Kallus and the droid departed from the outpost, leaving behind a subspace transponder for Coleema to use in contacting the Alliance in the future if needed. After Dee-Four and Kallus's departure, the bounty hunter IG-88 assassin droid IG-88 kidnapped Coleema. The bounty hunter transported them to a planet housing the Holowan droid foundry to gain access to their [brain](/article/brain], but the grand-engineer managed to escape. Later, Kallus and Dee-Four located Coleema on the planet and escorted them aboard the starship Glimmer of Hope following the activation of the subspace transponder by the reprogrammed droid Are Zero Are Zero. Aboard the ship, Dee-Four extended a welcome to the engineer and informed them of the circumstances of their rescue.
Dee-Four made an appearance in "A Rebel Bounty," a short story featured in the Star Wars Adventures Annual 2020 comic-book. Nick Brokenshire both wrote and illustrated the story, which IDW Publishing released on November 18, 2020.