Yu Tong, a fire investigator with the Qingdu City Fire Brigade, faces a perplexing case of spontaneous combustion in a lake on his very first assignment. His exceptional skills quickly catch the attention of the brilliant detective Lin Yaoyao. Despite their contrasting personalities, they must work together to unravel a series of mysterious fire incidents. As they delve deeper into the investigation, hidden layers of Yu Tong's character emerge, and an old case from his past resurfaces, leading t...