In 2016, the Assassin leader Gavin Banks ordered her to assist another agent, Griffin. Yanmei provided a jet to Griffin and the teenagers Natalya Aliyev, David Collins, and Javier Mondragón on their way to the Tomb, but the jet was shot down by the Templars. Surviving the crash, the Assassins confirmed the location of the Abstergo camp. As they made their way to the tomb on foot, David went towards the Abstergo camp, believing a series of lights were signalling him that Grace was there but was captured by the Templars.
Upon reaching the spot where Natalya desynchronized, she still refused to give up the location of the tomb, refusing to trust the Assassins for their absolute obedience to their Creed. However, Yanmei managed to convince Natalya to lead them to the tomb. Natalya did not want to help the Assassins but Yanmei managed to convince her to help by explaining to them the meaning of true meaning of the Creed. She and Griffin were subsequently knocked out by Natalya using sleeping darts when Natalya thought the Assassins would use the Trident of Eden for their own ambitions like the Templars. Soon afterwards, the Templar Isaiah arrived; the Assassins regained consciousness and attacked Isaiah while Javier escaped with his friends. Isaiah emerged from the tomb with the fear prong and used its power against everyone. Yanmei tried to attack him, but Isaiah ended her life before she could strike.