13 reasons why S4 is based on the further investigation of a murder cover-up in Liberty High and to end this series with graduation for good because the series lost its purpose after its 1st season and afterwards it was kind of sending mixed messages to the audience becoming more like Riverdale-ish. I will give this season a hard 6 out of 10.
SPOILER-AHEAD:-
Season 4, Initially is filled with more of clay's anxiety episodes rather than reality so it becomes confusing to distinguish whats reality and whats just his mind playing to him at one point. Jessica too starts having her PTSD experiences regarding Bryce thus, making all of this look like everyone is suffering from keeping secrets and they want this to end but the new-face in Liberty High, Winston makes it more troublesome for them as he becomes closer towards the actual killer of Bryce by each ep. The football team also suspects Monty being framed for the murder and teamed up with Winston and Monty's sister to get to the truth which at that point seems really intriguing. Alex also comes out as gay which is weird and felt to me like his character was forcefully pushed to being gay by writers. The story starts falling off the cliff when Clay starts forgetting things which he did like vandalism in school, Blowing Principal Bolan's Car, etc... . Then all of a sudden it went from a murder investigation to Justin dying of HIV and like every season they again showed a death of student bringing change which sends kind of false msg i think as the character Justin developed more than any other character throughout the series. By the end Winston gets to the truth by confession of Alex only and he decides not to go the police as he started loving Alex too. It concludes by everyone graduating and getting into College somehow bringing the story to its official end.