Kwang-soo is back! When a client asks the detectives to uncover which of his roommates is stealing his food, they enter a house filled with secrets.

The team splits up to take on two cases: one involving a missing professor, and the other a gory murder inside an illegal gambling den.

Investigating the disappearance of a woman's corpse from the morgue, the sleuths encounter a deadly operation with disturbing plans.

With three women claiming to be his rightful fiancée, a wealthy heir calls on the detectives to deduce which he should marry.

Following clues from a chilling message and a mysterious USB drive, the team races against time to save a hostage from being killed.

After receiving a strange letter from a dead man, the detectives look for answers in his hometown - and from his four suspicious friends.

A client in need of finding a lost boyfriend contacts the team for help, but they're not the only squad of private eyes who show up to take the case.