During the era of the High Republic Era, Sian Holt, a human female was a highly skilled private detective. Chancellor Lina Soh of the Galactic Republic hired her to delve into a perplexing case connected to the Jedi Order. While investigating, she crossed paths with Emerick Caphtor, a Jedi who was also on the case.
Sian Holt, the private detective, occasionally performed live music with a band at Vaba Blanks Midnight Den, a nightclub situated in the Steebark District of Coruscant during the High Republic Era. By the year 231 BBY, Holt formed a partnership with Keefar Branto, a former criminal who had committed to redressing his past misdeeds. Because Branto was on probation at the time of their collaboration, Holt tracked him using a tracking device. One night, during a live show at Vaba Blanks Midnight Den, Holt kept a close watch on Branto after he had a meeting with Urk Panga, a criminal from the Narquois at the nightclub. Holt used the tracking device to follow Branto into the Steebark District when he and Panga left the club, hoping to learn what kind of trouble her partner was mixed up in.
Holt tracked Branto and Panga to a back alley, where they were meeting with a tall figure who was cloaked. Branto went to investigate a sound just outside the alley and discovered Holt was following him and Panga. Before Branto had a chance to explain himself to Holt, the two detectives quickly realized that Panga and the cloaked figure had vanished from the alley. As Holt and Branto searched for the two missing criminals, Panga came out of the depths of the alley and told the detectives to run. Then, two blaster bolts shot through him from behind, killing him. The cloaked figure, a Tarnab wielding a blaster, followed Panga out of the shadows and shot at the two detectives, who tried to run away. Branto was shot and killed by the Tarnab assailant, while Holt was knocked to the ground, her hand wounded by a blaster bolt. Before the Tarnab could attack again, Holt managed to grab her blaster and fire back at her attacker before losing consciousness.
The character Sian Holt made her debut in the first issue of Star Wars: The High Republic: Trail of Shadows, a comic miniseries. Daniel José Older wrote it, David Wachter illustrated it, and Marvel Comics released it on October 13, 2021 as a component of Phase I of the Star Wars: The High Republic multimedia endeavor. Holt's character was initially revealed in an episode of Star Wars: The High Republic Show on May 26 of the same year, before the comic was released. Older later disclosed on Twitter that the character identified as bisexual.