In the 1990s, Cai, a foreman on an MRT tunnel project, leads his crew of workers into the depths of underground construction. In order to pay for his daughter’s music classes, with his co-workers, each with his own dreams, they unexpectedly unearth a mysterious katana deep within the tunnel, after which a series of uncanny coincidences begin to unfold. In the meantime, Mei-li, the first female construction chief in Taiwan, was striving to prove herself in a site dominated by men. However, because of that, she experienced a journey full of crises. As the project progresses, workers begin to exhibit symptoms of decompression sickness. When the answer surfaced gradually, where were those people supposed to go? In this drama of workplace politics, mysteries and relationships, let’s see if these invincible underdogs were able to ask God for something. Was the mysterious power in the tunnel a blessing or curse?