The following contains spoilers for The Sandman Season 1, Episode 3, "Dream a Little Dream of Me," now streaming on Netflix.
Jenna Coleman's Johanna Constantine is one of the many Sandman Universe characters who appears in the Netflix adaptation of Neil Gaiman's The Sandman. Based off of John Constantine's ancestor from the comics and John himself, Johanna gives audience members the best of both characters. Not only does the ancestral Johanna briefly appear in one episode set in England's past, but her modern descendent gets a full episode to herself with a storyline that's near identical to John's in the original Sandman comic.
In The Sandman Season 1, Episode 3, "Dream a Little Dream of Me," Morpheus is searching for the tools that were stolen from him when he was imprisoned by Roderick Burgess in 1916: his magic sand, his ruby and his helm, all of which are scattered to parts unknown. After consulting with the Three Fates, Morpheus locates the last known person to possess his sand -- which brings him to Johanna Constantine in 2022.
Like her male comic book counterpart, Johanna is established as a sorceress and an occult detective who investigates demonic activity and other supernatural phenomena. She also specializes in exorcisms, which she is hired to perform in "Dream a Little Dream of Me" when she is summoned by a priestess about to marry an English princess with a demon. Johanna successfully performs the exorcism, but there is something troubling her: a previous failed exorcism that resulted in the death of a child.
This failure has left Johanna with intense guilt and remorse to the point of having recurring nightmares about the event. In exchange for helping him locate his sand, Morpheus agrees to relieve Johanna of her nightmares, which forces her to confront her past. This brings her back to the flat of an ex-girlfriend named Rachel, whom she abandoned after she left for a case and never came back. Johanna unwittingly left the sand in Rachel's flat, which kept her alive until Morpheus recovered it.
Between Johanna's episode and John's storyline from the comic, very little has changed. Like John in the comics, Johanna also originates from Liverpool in Lancashire, and Johanna is described by her ex-girlfriend as a "selfish, ruthless coward." Both John and Johanna are humanists at their core who are driven by a desire to do good. They also have a profoundly cynical outlook on the world, which informs so many of the decisions they make in life, as well as the relationships they form and later abandon.
By not finding much value in human relationships, both John and Johanna don't put much effort into pursuing them long-term and always run away when things get serious. When they similarly hit brick walls in life, John and Johanna are depicted as distracting themselves from their problems through their work rather than confronting them head on. Another way Johanna is similar to John is that she's also foul-mouthed and rude to the people she interacts with. She is also established as bisexual, having had relationships with men and women over the course of her life.
One thing that does differ between the two characters, however, is that Johanna is better dressed and maintains a cleaner appearance, which is a stark contrast to John's more disheveled, beaten-down look. Johanna is not shown to be smoking at any time throughout her episode, which is another difference between herself and the chain-smoking John. Beyond those two differences, changes, Johanna in Netflix's The Sandman is very much the same character as John, while being very loosely based on John's ancestor. Fans of the comic antihero have already found much to love about the Netflix character and are clamoring for a Johanna spinoff.
The Sandman is now streaming on Netflix.