Danny Desai spent 5 years in juvenile detention after killing his aunt when he was 11. His best friends, Jo and Lacey, were in his backyard at the time, and the first ones to see the body. The series starts with Danny returning home to live with his recently-widowed mother, who was unable to sell their house so that they could move to a new town. Danny is universally hated in town but tries to reconnect with people, including Lacey and Jo, who stopped being friends shortly after Danny left-Jo is now an outcast nerd, while Lacey is an It girl. Things get worse when, right after Danny returns, one of Lacey's best friends is murdered, and Danny becomes the prime suspect.
I was really, really into the first half of the season, then a plot development happened that made me very uncomfortable in terms of narrative priorities, and then as soon as the show moved on from that, it kinda...got completely lost. Watching it, I think it was conceived as a 12-13 episode season but ended up being longer, and it feels like they're making things as they go along at times in later episodes. I still liked it, though, and plan to watch season 2 (If there is one? I haven't seen anything either way.) and it's pretty easy to see why it's been recced as something to check out if you like PLL, even if it isn't as female-friendship focused.( spoilers )