This show was on thin ice when they pulled ‘actually she was craaaaazy all along and didn’t know it’ with the episode based on the Nutshell Murders lady right before.
Anyway, it goes like this: They set up a mystery and then went ‘oh fuck it, it was a delusional lesbian trope what did it. No actual hints given except a sore hand’
The end!
F- for forgetting how to write a mystery.