In a way, Joe predicted the end of Edward and Nadia’s relationship.
During the first episode of this seasonjoe said eduardo and nadia they would kill or marry each other.
The two end up dating during the second half of the fourth season, until Joe kills Edward and frames Nadia for his murder.
Joe made it look like Nadia killed Edward, which is what he predicted.
Phoebe’s stalker was mentioned in the first half of the season.
An item displayed on episode one of this season revealed that Phoebe had previously had multiple stalkers.
Although this seemed like a random detail, we now know that it foreshadowed the plot with Phoebe’s current stalker, Dawn.
An article on Eat the Rich Killer includes Dawn’s diagnosis of Phoebe.
The title of the article “Eat the Rich Killer is Erotomaniac” seems to confirm that Phoebe’s assessment of her stalker was correct.
The term erotomaniac, a rare delusional disorder in which an individual believes another person is in love with him, returns later in the season when Joe wonders if it applies to him.
Joe’s status as an unreliable narrator has been foreshadowed since the very first episode of this season.
In the first episode of the season, Joe assign your students “The Tell-Tale Heart” by Edgar Allan Poe.
history portends Joe dismembering a body later that night, but can also be seen as a important clue towards the biggest twist of this season.
The main character in this Poe story repeatedly insists that he is sane even though his psychological state is falling apart, and Joe does the same throughout the season. The main character is also an unreliable narrator, also revealed to be Joe.
You can see Joe getting takeout for Marienne throughout the first part.
Already in the opening minutes of the season, Joe is seen carrying a red Tandoori Tradition bag to his apartment.
After it is revealed that he captured Marienne and is giving her takeout, the moments where Joe is holding a red bag during the first half of the season are turned into a timeline showing when he remembered to buy her food.
Joe’s peanut oil dream sequence is a reference to Benji’s death in the first season.
Joe has a dream in which he accidentally kills Marienne by putting peanut oil in her coffee.
In the dream, he says that this can’t be possible, as he would have known if she had a peanut allergy.
The moment calls again Benji’s death in the first season. — Joe killed him by putting peanut oil in his coffee to induce a fatal allergic reaction.