湛藍牢籠

Our protagonist Ren and his friends are onboard a high speed rail train, which is a tourist attraction that goes through the belly of the sea. What they do not know is that once upon a time, the train is a vehicle for time travel experience.
The joyful journey quickly spirals out of control when the train derails, locking everyone in the moment of the bloody incident that endlessly repeats itself.
Ren happens to be the only person that remembers each and every fateful loop. But what’s even stranger — with each repeating loop, one more of his classmates dies before the train’s derailing moment. A mysterious murderer has appeared, and in the name of deliverance hunts down and kills Ren and his friends......