In Grease 2, Didi Conn's beloved Frenchy (real name Francesca Alicia "Frenchy" Facciano) disappears halfway through the film for no apparent reason. The beauty school dropout initially shows Maxwell Caulfield's Michael Carrington around Rydell High - at the behest of her old friend Sandy - but then around halfway through the film she just vanishes.
Frenchy's disappearance is just one of the issues with the sequel, but Grease 2 was always going to happen after the unexpected success of the original. Four years after Randal Kleiser's adaptation of raunchy stage musical Grease was released and became hugely popular, Patricia Birch returned to Rydell High for Grease 2 and a new school year. She brought in newcomer Michelle Pfeiffer to lead a new crop of Pink Ladies and stage star Maxwell Caulfield as Michael, an exchange student and cousin of Olivia Newton-John's Sandy from Grease.
Grease 2 was received far less positively than the original and though retrospective reviews have been significantly more kind, at the time, it was criticized for being little more than a retread of the original. That wasn't helped by the presence of several members of Grease's cast (though the intention to have Olivia Newton-John's Sandy and John Travolta's Danny cameo wasn't followed through on), including Didi Conn's Frenchy. Given how important she seems at the start of Grease 2, her disappearance is confusing, so why did it happen?
Grease 2 is now considered an underrated sequel, with some great songs, but the writing is flawed and the decision to drop Frenchy stands out as one of the biggest issues. And both problems likely come from the same source: the fact that Grease 2's script was unfinished even as filming began. According to Didi Conn in an interview years later, the first draft director Patricia Birch was working from still included Frenchy, but as the script was finished, she was written out and Conn was told she was no longer required for filming.
The pre-production and filming process for Grease 2 is best described as chaotic: big plans like cameos for Grease stars Olivia Newton-John and John Travolta, as well as others for Stockard Channing (Rizzo) and Jeff Conaway (Kenickie), fell through and the original star Timothy Hutton was replaced by Maxwell Caulfield after being hired. On top of that, comedian Ken Finkleman was asked to write a whole new script from scratch on short notice, with filming starting before he turned in the final draft. Didi Conn described the whole process as "rushed, frantic, and unorganized."
Despite cutting Frenchy, the filmmakers decided to keep her in the final cut, even though they had limited footage. They also cut a key sequence in which she teaches Michael to rise a motorcycle and become his secret Cool Rider alter ego, despite that offering something of a conclusion to her arc. Instead, fans were left to wonder precisely why she just disappears: and it seems the answer is simple... the makers of Grease 2 realised halfway through that they just didn't want her. Perhaps she'd get better treatment if she returns (even briefly) in the upcoming Grease prequel movie.