On occasion, Master Nu overestimated the extent of her knowledge of the information contained in the archives and its completeness. After thirty years as Archives Director, Jocasta Nu came to feel that there was no information in the galaxy not contained within the archives. One such occasion occurred shortly before the Clone Wars when Obi-Wan Kenobi was investigating an assassination attempt on Senator Padme Amidala. When the assassin was killed by dart of Kamino origin, Obi-Wan hoped to learn about the planet from the archives before traveling there to investigate.
However, when his searches did not turn up results, he sought the help of Master Nu. While Jocasta had not heard of Kamino herself, she falsely concluded that if it did not appear in the archives it did not exist. Jocasta's overconfidence in the completeness of the archives blinded her to the possibility that a skilled Jedi Master could have altered the archives records. Luckily, Obi-Wan was only slightly deterred by this setback and with a little ingenuity eventually located the planet.
In the subsequent years, Jocasta Nu maintained her position as the Clone Wars spread across the galaxy. She was in the Jedi Archives the night Darth Vader stormed the Jedi Temple with the 501st Legion to kill all the Jedi within. When Darth Vader made his way into the archives, Jocasta Nu drew her blue lightsaber to confront the powerful Sith Lord. Darth Vader demanded access to the Jedi Temple's signal beacons, but Jocasta refused. Seizing her with the Force, Darth Vader lifted her into the air and impaled her on his lightsaber, bringing Master Nu's life to an end. The ensuing battle within the Jedi Temple would inflict much damage on the Jedi Archives to which Jocasta Nu devoted herself for so many decades.