Warning! Spoilers ahead for Young Sheldon season 6, episode 18. Although not as exciting as its predecessors, Young Sheldon season 6, episode 18 featured several subtle clues about what the future lies for the Coopers. Following another min-break, The Big Bang Theory spin-off returns this week with a brand new outing that moves Sheldon and his family's arc forward. With only several episodes left before it wraps up its current year, certain ongoing plotlines get some major developments, hinting that a culmination is on the horizon. Surprisingly, however, Young Sheldon season 6 also introduces an entirely new plotline that could function as a setup for its special one-hour finale.

Admittedly, Young Sheldon season 6, episode 18, "Little Green Men and A Fella's Marriage Proposal," felt a bit of a letdown, considering how solid the writing has been for the show recently. Unlike its predecessors that tackled the birth of Mandy and Georgie's baby, Baby Ceecee, and Missy's attempt to run away from home, nothing really significant happened in the outing. At this point in the season, it seemed more like a filler episode, which was underwhelming. That being said, some smaller moments in Young Sheldon season 6, episode 18 are either a direct setup for what's happening next or an indication of what's to come in the family comedy.

4 Mandy Answers Georgie's Young Sheldon Proposal (Kind Of)

Despite being already spoiled back in November, Georgie's twist proposal in Young Sheldon season 6, episode 17 was still a massive surprise. CBS did play it up by keeping viewers hanging for an answer for two weeks while the show took another break. Luckily, "Little Green Men and A Fella's Marriage Proposal" didn't prolong the mystery further. It picked up immediately after Georgie asked Mandy to marry him, but instead of a resounding yes, he was met with hesitation from her.

Hurt and somehow humiliated, it drove Georgie to act up the whole outing. Ultimately, however, they patched things up, keeping the possibility of marriage on the table.

The Big Bang Theory already revealed Mandy and Georgie's future, however. Per the nerd-centric sitcom, the pair will eventually tie the knot, with Baby Ceecee's mom becoming Georgie's first wife. Mandy Not fully turning down his proposal in Young Sheldon season 6, episode 18 indicated that CBS is sticking to established canon when it comes to their romance. With the family comedy's season 7 already guaranteed, it has more than enough time to continue developing the couple's storyline.

Perhaps the pair's wedding could even be Young Sheldon's series finale.

3 Missy Gets Close To The Sparks (& Potentially Sets Up A Popular TBBT Theory)

Ignoring Missy has been Young Sheldon's biggest mistake. Sheldon's twin sister may not be as intellectually-gifted as he is, but she is far better in all other aspects. She is witty, charming, and emotionally mature. When some of her family members were having a difficult time in Young Sheldon season 5, she was there for them. However, this also relegated her to a supporting player instead of a primary character.

Late as it may be, Young Sheldon season 6 has started to address this issue by putting her at the center of its storytelling.

On the heels of her runaway episode with Paige, Missy got involved with the Sparks family after she told Brenda about a mean girl in school that was looking to prank Billy in Young Sheldon season 6, episode 18. The pair's conversation was brief, but it paved the way for another Missy and Billy moment in Young Sheldon. CBS has noticeably been developing the pair's friendship, which has been one of the more unexpected partnerships in the series. This could very well be a setup for a long-standing theory that Billy becomes Missy's unnamed first husband in The Big Bang Theory.

2 Sheldon Embarks On A New Mission & Starts A New Partnership

Despite being the titular character of the show, Sheldon is no longer the center of Young Sheldon's attention. CBS has diversified its storytelling, giving ample focus on other Cooper family members. After his grant database project arc fizzled out, The Big Bang Theory prequel introduced a new personal arc for the boy genius in "Little Green Men and A Fella's Marriage Proposal." In the episode, Sheldon embarked on a new scientific exploration attempting to find life on other planets.

He went around East Texas Tech to find a professor who would back up his endeavor, but even Professor Sturgis was skeptical of the idea.

Without the help of his usual collaborators, Sheldon teamed up with a new teacher at East Texas Tech: Dr. Prakash. Nothing really happened in this plot, and there was no payoff to their efforts. That being said, this new fixation could ultimately be what motivates Sheldon to go abroad for the summer. As revealed in new details about the Young Sheldon season 6 finale, the send-off will see George and Mary's son going on his first international trip for a study program in Germany.

1 Young Sheldon Officially Skips George's Cheating Scandal

Sheldon didn't have good things to say about his dad in The Big Bang Theory. He often chastised him for being drunk and negligent, but his most brutal story about George came in season 11. While explaining the origins of his three-knock rule, Sheldon recalled catching his father in bed with another woman when he was 13 years old. According to him, it happened over the spring break when he unexpectedly came home from college.

Young Sheldon season 6, episode 18, however, established that said spring break is already done, with Sheldon back in school.

This means that Young Sheldon is effectively ignoring George's cheating scandal. While there's a possibility that CBS is saving the narrative in season 7, it will still no longer be accurate to Sheldon's story. As someone with eidetic memory, it's difficult to argue with the boy genius' memory. There's also no incentive for him to lie about such a traumatic experience, meaning that it's highly unlikely that he made the incident up. Whether Young Sheldon has any intention of resolving this new plot inconsistency is currently unknown. If it does, however, it won't happen in season 6.

Young Sheldon season 6 airs Thursdays on CBS.