Spoilers for The Walking Dead Season 7 Episode 15 follow.
During Negan's interrogations of Sasha, the villain in charge of the Sanctuary and its Saviors mentioned that "a little birdy" told him that Rick Grimes and the people of Alexandria are up to no good.
The statement was overlooked by some fans. The immediate concern was regarding Sasha's well-being and whether or not she is going to join Negan's army as Eugene has, fight him and lose, or succeed in killing the most hated face on the AMC series.
However, Negan's knowledge of Rick's rally against the Saviors is the most important element of this penultimate episode of Season 7. With only one episode left, Negan is likely going to march over to Alexandria and vent his frustrations to Rick and his people.
This, however, means someone Rick trusts has betrayed him.
Who was it? We explore the possibilities on the following slides.
The leader of the junkyard gang has given Rick little reason to trust her. She is playing in a win-win game. If Rick brings her guns, she is armed for war. If she aligns herself with the Saviors, she has resources and is still armed for war.
In fact, aligning herself and her group of Scavengers with Rick would put Jadis' people more at risk than aligning herself with Negan.
Jadis is the most likely candidate to have tipped Negan off about Rick's plan to fight. She is fully aware of Alexandria's intentions. She does not like bargaining. Rick has shown her his harder side during negotiations. All of these things have likely turned the junkyard gang's leader off to the thought of helping Rick and may have, in fact, turned them into an enemy.
Eugene was made aware of Rick's plans when Rosita and Sasha showed up to the Sanctuary. In their efforts to rescue him from the villain and his group, the two women informed Eugene that Alexandria is going to fight them.
Eugene turned down their offer and rushed back inside of the Sanctuary, remaining loyal to Negan.
Given Eugene's loyalty to Negan, it's not unlikely that he repeated Sasha and Rosita's words in a conversation to Negan, making the villain aware of Rick's plan.
Eugene doesn't seem to fit the bill as well as Jadis, however. His betrayal would be less surprising and dangerous for Rick's group. Still, he is a candidate but likely just that.
No one trust Gregory.
Plus, Gregory had a conversation with Simon last weekend which ended with an exchange of words that the audience could not hear.
In the comics, Gregory tips the Saviors off to an incoming attack from Rick, the Hilltop, and the Kingdom. Negan presents him to the army as he shouts, "The Hilltop stands with the Saviors!" Still, a battle ensues.
However, Gregory was seen at the end of Episode 7x15 digging out a map and planning a trip to the Sanctuary with Cal. He might be due for his betrayal but it doesn't seem likely to have already happened.
Like Eugene, Gregory is being rule as a candidate and just that. The safe bet here is that Jadis and her junkyard gang have gone behind Rick's back to align themselves with the Saviors, pitting Alexandria in an ugly disadvantage for a fight in the Season 7 finale.