Lucifer seeks an antidote to the Professor’s poison, which sends him on a mission to hell to locate the Professor’s soul. While there, he confronts his guilt about Uriel’s death. Meanwhile, Mom travels to hell to return Lucifer, who feels betrayed by his parents after a revealing discovery.
Lucifer and Chloe go after a masked murderer who is poisoning college students, while at the same time try to adapt to their new relationship. Meanwhile, Charlotte seeks Linda’s advice on a touchy subject.
After Lucifer and Chloe have an interrupted “moment,” the tension between the two of them makes it difficult to investigate the murder of two victims, who happen to be Lucifer’s ex-flames. Since Lucifer seems to be the only connection, interviews are conducted with his recent paramours and a surprising connection is made that helps lead them to the killer. Meanwhile, Charlotte continues to try and manipulate Chloe and Lucifer’s impending romance and a larger threat is revealed.