"When an ecstasy cook-turned-chemistry-teacher is found murdered in a cozy Los Angeles suburb, Lucifer and Pierce must go undercover to help track down the killer. Meanwhile, Maze has a newfound attraction for someone that she used to despise and Charlotte has a revelation."
Lucifer HAS been paying attention during his therapy sessions with Linda, as he was able to emmulate a therapist quite well.
Lucifer mentions that he wants to find Marcus Pierce's "Kryptonite". This is a likely reference to Tom Welling's, who portrays Pierce, previous role as Clark Kent in Smallville.
When Lucifer and Marcus Pierce are undercover as a couple, their pseudonyms are Luke and Marc, respectively.
Even undercover, Lucifer does not lie; he merely chooses more obscure words and phrasing.
In a sense of irony, from the information about the murder, it could have been prevented if the drug dealer had explained more thouroughly to the mistaken wife thst she wasnt having an affair with her husband, but was supplying him weight loss drugs.