Detective Ji Bai has to train a new recruit, the criminal profiler Xu Xu. Although she is great at determining one's thoughts, she doesn't know how to interact well with people. But that's not the reason why Ji Bai intend to fire her. She's very talented in the art of profiling, yet lacks in physical ability, running as slowly as a snail. Still, impressed by each other abilities, the teacher-student pair slowly fall in love in the midst of their investigations. Adapted from the novel “When A Snail Loves” (如果蜗牛有爱情) by Ding Mo (丁墨).