Synthesis is the pinnacle of evolution. But for the Catalyst to acknowledge it as a valid option to offer Shepard, it must be something in this galaxy, in this cycle, to change the variables. The Catalyst begins to search through the Alliance's network, hacking through all the data they have gathered since their existence. The search bumps into a video log, where synthetics and organics work together against impossible odds. The event shows EDI and Joker in a Cerberus base. While Hackett sends Alliance support to Shepard's squad in pursuit for the Prothean VI, EDI acquires information that the Illusive Man can hack her again and take control over her, and with it, everything the Alliance has learned so far. To protect her comrades and for the sake of her own survival, EDI separates from Shepard to locate and destroy this remote controller computer. Joker could not sit still and let her do this alone. He left Normandy in Cortez's hands and joined EDI against all the given orders, despite his condition. The attachment and symbiosis between this organic and this synthetic was already there, enough for the Catalyst to make a pause. Being the main base of the Cerberus faction, it had the most powerful forces defending it, including the individuals enhanced with reaper tech. And while Shepard makes his way to the Illusive Man's chair, EDI and Joker end up in the darkest corner of Cerberus' Main Base outnumbered by special Cerberus forces and worst nightmares that Cerberus experiments can produce. Their own hope now lies in each other. It took only one nanosecond for the Catalyst to find and process the audio and video logs from Alliance's archives, enough for the Catalyst's decision about Synthesis. And that decision is directly tied to EDI's and Joker's success, or to their ultimate demise.