One of the biggest mysteries heading into “Game of Thrones” Season 8 were the precise details of the deal Tyrion (Peter Dinklage) made with Cersei (Lena Headey) in the Season 7 finale. In that episode, Tyrion meets privately with his sister to try to convince her to send her army north to help in the fight against the army of the dead. As they’re talking, though, he realizes she’s pregnant, and the scene cuts off shortly afterward. The next thing we know, Cersei is rejoining Jon Snow (Kit Harington) and Daenerys Targaryen (Emilia Clarke) at the Dragonpit to tell them she’s suddenly changed her mind and will send her army north after all. Uh, what? She was, of course, lying to everyone. Cersei never had plans to send her army to fight, a point viewers thought Tyrion should’ve picked up on from the start. This left two possibilities: Either Tyrion’s planning something diabolical behind the scenes with Cersei, or his decision-making skills have become as crappy as the sewers he was in charge of at Casterly Rock. Much evidence supports the former supposition. In the meeting with his sister, Tyrion tells her, “I don’t want to destroy our family. I never have.” There’s also a moment in the Season 8 premiere where Sansa (Sophie Turner) drags him for trusting Cersei, saying, “I used to think you were the cleverest man alive.” This comment is immediately followed up by Bran (Isaac Hempstead Wright) staring ominously at Tyrion from the courtyard. It all seemed very suspect. However, the second episode of Season 8, “A Knight of the Seven Kingdoms,” seemed to finally confirm no deception marked the deal with Cersei. She really did trick him.

After Jaime (Nikolaj Coster-Waldau) says Cersei never planned to head north during his trial at Winterfell, Daenerys becomes the voice of the fans, blatantly telling Tyrion: “Either you knew Cersei was lying and let me believe otherwise, or you didn’t know at all, which makes you either a traitor or a fool.” So which is it? Apparently, he was just a fool. Tyrion reveals to his brother what else happened in the meeting with Cersei, saying he made a mistake common among clever people: underestimating his opponent. “Cersei told me the pregnancy had changed her, a chance for you both to start again, and I believed her,” he said. But should we believe Tyrion? In recent interviews with HuffPost, both Bryan Cogman, who wrote Episode 2, and Jaime Lannister himself, Nikolaj Coster-Waldau, said that we should. “I think he did [trust her] because, in his mind, the only time she’s really acted in a way that wasn’t utterly selfish was in regard to her children,” Cogman said. “The fact that she told him she was pregnant, and then he — on a real brother- and-sister level because of his history with her — believes that she was, that it would be one of those moments where love of her children trumps her own selfish ambitions, so I think that precedent is what made him confident about that.” He added, “And Cersei is smart enough to know that he would think that.” Asked whether there was anything underhanded going on with Tyrion, Coster-Waldau told HuffPost, “No, God, listen, Jaime, he loves his brother. That’s the thing, it was a beautiful scene by the fireplace and it was nice for Tyrion and Jaime to have a moment where they go, we still love each other and we’re good. I mean, he still killed their father, which is a really uncool thing to do, to kill your parents. But at the same time, there’s no one Jaime trusts more than Tyrion apart from, I think,” Ser Brienne of Tarth (Gwendoline Christie). Unless we’re going to think that Tyrion, Cogman and Coster-Waldau are lying, it seems Tyrion really did fall for Cersei’s ruse.

Helen Sloan/HBO Tyrion. He drinks and doesn't know things.

It’s weird Tyrion seemingly bought Cersei’s change of heart so easily, and understandable that fans theorized he was secretly working with his sister. Not trusting Cersei is “Game of Thrones” 101, after all. But Tyrion’s decision-making has never been flawless. In Season 2, he devised a plan to send Cersei’s daughter, Myrcella (Aimee Richardson/Nell Tiger Free), to Dorne to create an alliance, meanwhile feeding false information about the decision to the small council to weed out which advisers were leaking things to Cersei. At the time, it seemed like a brilliant plan, but a few seasons later it resulted in the loss of Myrcella, who died in her father Jaime’s arms after a poisonous kiss in Dorne (not an ideal outcome). Even if there was no collusion with Cersei, you can’t exonerate Tyrion of future obstruction. There’s just too much foreshadowing and creepy stares from Bran to ignore. Perhaps it’s HBO’s “Game of Thrones” and “Sesame Street” crossover promo that’s actually giving us a hint at how Tyrion’s allegiances will play out — with both he and Cersei hearing Elmo’s advice and deciding to respect one another and work together.