A neural core was a droid part, that according to the Eye of Webbish Bog, was what some might say was the sentient equivalent of a soul. After the destruction of the droid insurgent Ajax Sigma during the High Republic Era, his neural core was taken and preserved. Centuries later, the core was concealed inside an urn and passed from hand to hand until between around 8 BBY and 2 BBY, when it came into the possession of Augustus Graves, the CEO of the Corellian Engineering Corporation. The Hutt gangster Jabba Desilijic Tiure learned of the urn, and sent the smugglers Han Solo and Chewbacca, as well as the bounty hunter Greedo to the planet Corellia to retrieve the urn, though he informed the trio that the urn contain the ashes of Krestrel D'Naran, his archrival. By the time, the three broke into Graves' penthouse, however, he had sold the urn to the former sava Madelin Sun on Antillion, who kept the urn in her collection. Solo and Chewbacca, and the criminal Corbus Tyra, who was posing as the father of Solo, made their way to Antillion to acquire the urn from Sun, which they eventually did. Graves, however, hired the bounty hunter Krrsantan to capture Solo, believing he had the urn. Solo insisted to Graves that it was still on Antillion, though in reality Tyra had recovered it when Krrsantan left with Solo and stored it aboard the Millennium Falcon.
The Falcon was later impounded by the Galactic Empire on Iakar, and the urn, having been deemed of value, was sent to the office of Grand Moff Wilhuff Tarkin on Coruscant. Solo, Chewbacca, and the criminal Phaedra later successfully recovered the urn from Tarkin's office though when it was dropped by Solo, it opened, and Phaedra discovered that it did not contain ashes as they had been informed before. Unsure of what the neural core actually was, they made their way to Nar Shaddaa where former Sava Korin Pers told them what it was. Eventually Solo and Chewbacca buried it in an attempt to hide it, though it was later dug up and given to followers of Sigma who had built a new body for him on Mechis III. They then placed the neural core in Sigma's head, restoring his mind.