In 2012, Desmond and William Miles had to retrieve three power sources located in different cities around the world. For the first one, Desmond traveled to New York City, climbing One World Trade Center and parachuting onto the building that contained the power source. After he retrieved it, he was confronted by the Master Templar Daniel Cross, whom he knocked out with the artifact.
The second artifact was in possession of a woman who was spectating a mixed martial arts tournament in São Paulo, Brazil. Desmond went to the room she was in but saw that Daniel Cross had made it there first and killed the woman, taking the artifact. He ran out of the room and tried to escape, but Desmond eventually caught up to him and took the power source from him after a fistfight.
The third power source was located in the Egyptian Museum in Cairo, Egypt. Desmond was prepared to retrieve it but was told he needed to stay and find the Grand Temple Key through Ratonhnhaké:ton's genetic memories. William then left for Cairo to acquire it in his stead, but was later captured by Juhani Otso Berg and Sigma Team.
In a video sent to Desmond's team, Dr. Warren Vidic proposed a temporary truce to their perpetual conflict to allow for an exchange: if Desmond peacefully came alone to Abstergo's Rome facility and relinquished the Apple of Eden to the company for their Eye-Abstergo project, Vidic would release William unharmed. Desmond refused to comply, instead storming the facility with the Apple and assassinating Cross before making his way to Vidic's office, where he used the Apple to kill Warren and the guards surrounding his father. Grabbing the last power source off Vidic's desk, Desmond and William walked out of Abstergo and returned to the Grand Temple. Back at their base, Desmond inserted the last battery, unlocking the Temple's inner chamber which held the global aurora borealis device.