Bodo Baas was a Jedi Master, and was a part of the Jedi group that lived in the Adega system. This was six hundred years before the Battle of Yavin, and when Baas achieved the status of Jedi Master, he inherited a great Jedi artefact; a Jedi holocron. This had been passed down through many generations, and it was used to record the stories of Baas and other Jedi, and could only be activated by another Jedi. There were several other holocrons in existence in the galaxy, and Baas became the Gatekeeper of his one.
During the great Jedi purge, Palpatine had Baas executed, and the holocron fell into Palpatine’s vile hands. As he was a Jedi, the Emperor unlocked many secrets from the holocron, but the deeper levels remained closed to him since he was not a Jedi of the Light Side.
Six years after the second Death Star was blown to bits, Leia gained possession of the holocron, after confronting the clone Emperor. She escaped on the Falcon, while Luke stayed behind to finish Palpatine for good. On the Falcon, the holocron activated at Leia’s touch, and she heard the story of Ulic Qel-Droma. She talked to the holocron once again back on Coruscant, and asked Baas about the fate of her brother. Baas could not tell her, saying this particular future was shrouded in mist and shadow.
Whether Leia still has the holocron is not known. But it was one of several, and if
these can be found, then the secrets of the Jedi can once again be revealed.