This is a study tour, but also an unusual one-a journey through time to have close contact with dinosaurs. Unfortunately, the protagonist encountered the legendary asteroid impact on Earth. In a critical moment, the protagonist narrowly escaped into a cave. Although the cave was tightly blocked by the fallen boulders, a snorting nose slowly appeared behind him… The most unfortunate thing in the world is no more than this. The subsequent series of stories not only posed a difficult choice between life and death for the protagonist, but also tested his morality and justice… Let’s travel through the time gate together and re-experience that unusual ancient world.