Ivy (Peyton List) begins to investigate "Project M", which is being conducted at Wayne Enterprises and involves the experimentation and deaths of several plants, much to her anger.
Simultaneously, Ivy hypnotizes Fox (Chris Chalk) and forces him to take her to the laboratory where Project M is being conducted and she collects a sample of the Lazarus water that is being used in the experiments before escaping.
In March 2018, it was announced that the thirteenth episode of the season would be titled "A Beautiful Darkness" and was to be written by Tze Chun and directed by executive producer John Stephens.
In March 2018, it was announced that the guest cast for the episode would include Cameron Monaghan as Jerome Valeska, and Peyton List as Ivy Pepper.
[3] With these ratings, Gotham ranked first for Fox, beating Showtime at the Apollo, fifth on its timeslot, and thirteenth for the night, behind Champions, How to Get Away with Murder, S.W.A.T., Superstore, Will & Grace, Scandal, Chicago Fire, Life in Pieces, Mom, Grey's Anatomy, Young Sheldon, and The Big Bang Theory.