Aaron is able to deduce from the get-go that Gamma is being tasked with getting info out of him.
Siddiq eventually realizes that the one thing the afflicted Alexandrians have in common is that they’re drinking from the same water source. He also realizes that Dante is a Whisperer sent to infiltrate Alexandria. Unfortunately, Dante kills him before he can reveal either of these things.
Becoming the Mask: Gamma shows interest in Aaron’s ways, and Alpha is very aware of this and whips her to remind her of her place. Dante suggests he has succumbed to this a bit as well, as he goes on about how great a place Alexandria is... even though he’s helping destroy it.
Siddiq’s first meeting with the masked Dante had the latter telling the former to open his eyes. Their last meeting in which Dante kills him has his last words to his victim being “close your eyes”.
In a meta-sense, the following episode of Talking Dead featured the return of Chandler Riggs, Carl’s actor. Carl died bringing Siddiq to Alexandria, so it’s fitting that Riggs return for Avi Nash’s final episode.
Lydia suggests that the Whisperers learning that a peaceful way of life is indeed possible would destabilize the Whisperers’ morale and thus Alpha’s control. In “We Are the End of the World”, a few Whisperers discussed taking over Hilltop for this exact reason, and Beta himself noticed as well.
Lydia began staying in Alexandria’s cell in “Silence the Whispers”.
Siddiq mentions following the extensive notebooks Eugene made to help take care of baby Coco in “Lines We Cross”.
In “Lines We Cross”, one of Siddiq’s episodes was triggered by a good look at Dante’s lips... which were the only part of his face visible when he was wearing his Whisperer mask.
Siddiq discovers that the Alexandrians are drinking unfiltered water. In "What It Always Is", Gamma was gutting walkers and dumping them in a creek that was part of Alexandria's water supply, explaining the spreading illness.
The Cameo: Matt Mangum makes a brief cameo returning as DJ in Siddiq’s PTSD episodes.
Character Death: Siddiq is strangled to death by Dante. Cheryl is also seemingly a casualty of Dante’s water tampering, before the next episode reveals that he actually smothered her with a pillow.
Cold-Blooded Torture: When the captive Whisperer literally spits in Carol's face for attempting to play good cop with him, she loses her patience and begins torturing him by puncturing his wound and punching him with her wedding ring on.
Daryl’s scars from his abusive upbringing were first seen in Season 3’s “Home”. His newest scar is from his encounter with Jocelyn depicted in Season 9’s “Scars”.
When Lydia says she’s had worse bruises, Carol agrees, alluding to her abusive marriage to Ed.
Siddiq confesses to Rosita how being forced to watch the massacre and not being able to do anything about it traumatized him. The look on Rosita's face makes it clear she is remembering how she had to witness the murders of her ex-boyfriend Abraham and Glenn right in front of her in Season 7's "The Day Will Come When You Won't Be"; though she doesn't explicitly say it aloud.
Death by Adaptation: Siddiq survived the entirety of the comic’s run in stark contrast to his TV counterpart.
A Death in the Limelight: Siddiq’s PTSD has been a major character subplot of Season 10, and this episode largely revolves around him before his death at the end of it.
Downer Ending: Dante is revealed to be a Whisperer and murders Siddiq in retaliation once again leaving Alexandria with no medic.
Evil All Along: Dante is a plant in Alexandria from Alpha.
Explain, Explain... Oh, Crap!: Siddiq is reflecting that he doesn't know how everyone is getting sick since they don't eat the same things or live together... but then he realizes they've all been drinking the same water. It's then he discovers that the water pump has been broken to say it's the opposite of what the sign says, meaning the Alexandrians have been drinking unfiltered water.
Face Death with Dignity: The flashback shows that DJ mustered up as much courage as possible when he was finally decapitated by Alpha. In the present, Cheryl realizes her time is up and says she’s made her peace.
Fingore: Daryl threatens the Whisperer first with removal of his fingers.
Forced to Watch: This episode confirms that Siddiq was forced to watch Alpha behead the pike victims right in front of him.
The opening shots of the worsening afflicted Alexandrians are accompanied by heavy focusing shots on the water they’re drinking, foreshadowing how they’ve been drinking contaminated water.
The captured Whisperer seems to regard Dante with something akin to familiarity, and is a little friendlier to him than his other captors. Later, he is extremely alarmed when he is dying of poison, clearly surprised that he’s dying in Dante’s care.
The captured Whisperer also says the truth is right in front of the Alexandrians, a subtle taunt about Dante’s true nature.
Siddiq’s attempt at suicide by drowning himself in the pond foreshadows how Dante kills him by suffocating him.
He Knows Too Much: Dante kills Siddiq when he realizes that Siddiq has recognized him from the pike massacre. It's also all but said that Dante poisoned the captive Whisperer to prevent him from potentially folding and betraying Alpha.
Locked Out of the Loop: The captive Whisperer believes the party line that Alpha killed Lydia. Only Beta is aware that Lydia is still alive and that Alpha would never kill her own daughter.
The Mole: Dante is a Whisperer plant in Alexandria.
Once More, with Clarity: Dante’s reveal clarifies a few things about how Alpha has been able to stay a step ahead of the group.
It seemed odd how Alpha knew the communities crossed her border during the winter considering the Whisperers fled south to escape the cold, and any lingering Whisperers almost certainly would not have survived without leaving behind traces for the communities to find. It’s now likely that Dante was the one who reported the crossing to Alpha, along with the other two crossings.
Dante is also likely how Alpha knew that Henry was Carol’s adopted son when she taunted her at the border.
Dante’s presence in Alexandria is likely one of the reasons why Alpha has not unleashed her horde on the communities and has settled for a long war of attrition. The next episode will confirm she promised to reward him if he successfully brought down Alexandria from within, implying she’s willing to keep her word to him.
The Reveal: Dante is a Whisperer spy in Alexandria who has been poisoning the water supply to slowly kill off the town for Alpha.
Spark of the Rebellion: As previous episodes confirmed, Lydia says that if the Whisperers can see that the normal way of life can thrive despite Alpha’s insistence it cannot, Alpha’s regime will crumble overnight and she’ll be helpless to stop it. Carol makes sure that Gamma can see Lydia to reveal Alpha’s lie to her, and it shakes the loyal Whisperer to her core. Dante, on the other hand, is a subversion. He admits to Siddiq that he has seen that Rick's way of life can indeed be possible, and he even knows that Alpha lied about killing Lydia, but ultimately he remains loyal to Alpha and kills Siddiq to keep his cover intact.
You Are Not Alone: Rosita sits with Siddiq after his suicide attempt and tells him this outright as she tries to help talk him through it.
