It's the apocalypse, and Seoyoung wakes up in a desolated world without any memories. He wanders around until he comes across Younghyun, an esper with the ability to summon and control fire. The two trek across a city of ruins, trying to recover Seoyoung's lost memories. But Younghyun seems too familiar with the city as it is. There's something he’s not telling Seoyoung, and it seems the two used to know each other from before. But he's all Seoyoung has for now… Both of them need a way out of their darkness, but could they be the guiding light for each other?