May（杰西卡·贝尔 饰）曾经过着看起来十分完美的生活，体贴的男友，舒适的工作，安静而美好，但她总觉得缺少点什么，因此她做了一个决定，去寻找真实的自我。 　　某天May结识了一名私家侦探，通过侦探，她找到了自己的亲生妹妹，并且惊讶地发现她妹妹的住所离她并不遥远。她们自幼分离，这次相见，她的内心充满了忐忑，不知道究竟是好是坏，如今她的妹妹已经改名叫做Shiva（Zosia Mamet 饰），很明显，Shiva的生活一团糟……

In the year 2961, the time is after humanity and nature has recovered the land. A hunter named Cygnus is called to rise above his duty. He provides for Last Arc, a once nomadic band of survivors in need of food and water that is now growing scarce. The answer must be found before a group of outlandish Heretics descend upon them. Cygnus must voyage across the treacherous landscape to defend his people. Sent by Nova, the matriarch of the band, she acts based on her vision for Cygnus to find a seed of hope. The future of Last Arc is for him to discover, Cygnus ventures into a hostile landscape in search of an answer for his people. On this journey of encountering many traps and dangers, Cygnus discovers what has been hunting him is his identity.