The fabled founding texts of the Jedi Order were sheltered from Ahch-To’s weather by the huge trunk of a once-mighty uneti tree. This collection of ancient tomes was painstakingly assembled by Luke Skywalker, but became a burden and a torment to him. Luke vowed to burn down the library, but repeatedly found himself unable to do so – until Yoda’s spirit called down lightning to do it for him. Luke didn’t know the library was empty: Rey had already spirited the Jedi texts to safety aboard the Millennium Falcon. She then studied them as part of her own training, learning of techniques such as Force healing and the existence of secret worlds such as Exegol.