In the first season, Sarah, the "Orphan Black," accidentally learned her true identity when she witnessed a suicide - she was the result of an unprecedented genetic experiment, and there are many people like her in the world. In the second season, Sarah began to search for her missing daughter Kira in a desperate race. Her "scorched earth tactics" triggered a confrontation with Rachel, who supported clones, which was precarious for all people like her. A carefully crafted world is about to get out of control, and Cosima's genetic disease threatens everyone. Sarah must negotiate with her enemies in an extremely dangerous environment to track down the truth of the laboratory. As Sarah learns more about her past, new mysterious people appear, but can they trust each other? There are ruthless new players in this world who are vying for control of Sarah's destiny.