It's sort of a mix between Ghosts and The Breakfast Club...in the first episode, a high school senior, Maddie, wakes up in the basement of her school and discovers she's dead. But she doesn't remember how she died. Wandering around, she discovers a sort of therapy group--think AA for ghosts--led by a (dead) teacher. Among the other ghosts are a jock, a nerd, a "weird" one (who looks so much like Ally Sheedy in Breakfast Club, it's uncanny...and had to be deliberate) and, oddly, a few ghosts who never speak. They all died in the school (seriously, what's with all the kids dying at school? And there's one group--members of a marching band that died in a plane crash--that didn't die at the school and why are THEY haunting the school?) and they're all trying to both figure out how to cross over and how to make the most out of their afterlife. But Maddie wants none of that "living your best afterlife"...she just wants to know who killed her.
The show is...not great. Peyton List, who played Emma on the Disney show Jessie, has the lead here and she's not really lead material, IMO. Too often she acts like she attended Joey Tribbiani's School of Smelling a Fart Acting. None of the cast, again IMO, is going to win an Emmy any time soon. The pacing was a bit slow for me and while there were the usual twists and turns (everybody has a secret!), I still figured out whodunnit by episode 8, which was the last. Well, I sort of figured it out...I'll admit THAT twist was pretty good. I was kind of hoping the show would be a one and done, as I have no real interest in a season two but would feel compelled to at least watch the opener, but the show, which also airs on...either Paramount+ or Peacock (I think the former) has already been renewed.
One thing I kind of enjoy: I love how "ghost rules" change depending on what show you're watching, or what book you're reading. For example, the characters on School Spirits can add to, subtract from, or entirely change their wardrobe any time they want to, but on Ghosts, what you died in is what you're stuck wearing forever.