The New Girl Storyline That Disappeared Without Explanation
Across its seven seasons and 146 episodes, "New Girl" usually did a good job at resolving its storylines, whether that meant having Jess (Zooey Deschanel) realize she needed more from Russell in Season 1 or Cece (Hannah Simone) and Schmidt (Max Greenfield) finally going ahead and tying the knot. The show's main characters slowly grew up for the better and made major steps toward change and responsibility, with Nick (Jake Johnson) even writing a successful novel and Jess eventually becoming a school principal.
"New Girl" also built an impeccable cast of supporting characters across its run, and it was great at bringing absurd fan favorites like Nadia (Rebecca Reid) or Bearclaw (Josh Gad) back to the show for more laughs. However, that's also why it seems especially weird that one of the show's characters was never brought back to the popular sitcom, even though they were really important to Jess and should have logically returned for some of the big events covered in the show's later seasons.
Abby Day showed up for three episodes and never returned
Abby Day (Linda Cardellini) is introduced in the "New Girl" Season 3 episode, "Sister," as the sister of Zooey Deschanel's Jess. The character ends up being the focus of a three-episode arc all about the impact she has in the loft and even on Jess' relationship with Nick. As played by Cardellini, Abby is spontaneous and hedonistic and very much unlike her responsible sister. That also means she's extremely chaotic, and consequently, she ends up becoming Schmidt's lover overnight and nearly moves into the loft.
Jess ultimately convinces her to be independent and assume some responsibility for herself though, which leads to Abby leaving Schmidt and Los Angeles at the end of "Sister III." It's a fairly neat, contained storyline, but it's weird because Abby is never really mentioned before Season 3 or after she leaves. In fact, she is never heard from or seen again on "New Girl," even when Nick and Jess get married. As a result, it feels like the "New Girl" writers had an idea to get Linda Cardinelli on the show, but pretty quickly realized the character didn't fit in it. Fortunately for her, Cardinelli has stayed busy with plenty of film and television roles in recent years, so we doubt she was all that bothered by her "New Girl" disappearance.
You can stream every episode of "New Girl," including the show's Abby-centric Season 3 arc, now on Netflix.