One rainy night, an Alpha medical student, Gong Jun, came across a wounded man collapsing in a dark alley on his way back home. He recognized this unknown man as an Omega, and he also discovered that there were people in the vicinity desperately searching for this Omega, bearing an obvious ill will. Afraid that those people might find them, Gong Jun decided to bring the man home with him and tended to his wounds. However, the man disappeared the next morning. Several days later, he showed up without notice at the pet cafe where Gong Jun was working part-time, introducing himself as Zhang Zhehan and expressing his wish to thank the younger man in person. Little did Gong Jun know, that this seemingly refined and gentle Omega was hiding a dark secret behind his tender smile.