Who Spray-Painted the School in '13 Reasons Why'? — We Admit We Were Surprised

*Warning: Spoilers for the final season of 13 Reasons Why*

A lot of questions arise in Netflix's controversial teen show, 13 Reasons Why. With the fourth and final season drawing the Liberty High series to a close, we're still left with some questions.

Like, who spray-painted "Monty was framed" on the school walls? Clearly, someone was in on the fact that Monty was not responsible for Bryce's death. Keep reading for answers, and inevitably, some spoilers.

Back in Season 3, Monty (Timothy Granaderos) was serving time in prison for sexually assaulting Tyler (Devin Druid), but then was killed by an inmate at the end of the season. Because he's dead, it was convenient to pin Bryce (Justin Prentice)'s death on Monty.

Of course, the road that leads to the mystery of Bryce's death is a long one, as many people were seen arguing or physically fighting with him at the homecoming dance. Even guilt-ridden Zach (Ross Butler), who confessed to the murder after beating him up to a pulp, is actually innocent — as it's, in fact, Alex who pushed him into the river, where he was unable to help himself because of all of his injuries.

But we might not even know to suspect any of the other students of Bryce's murder if it hadn't been for the spray-painted message, reading "Monty was framed" in red letters at school.

The person who was behind writing this message, unbeknownst even to himself, is protagonist Clay, who looks just as surprised as the rest of the students when he sees the stark lettering.

We actually learn later through his therapy sessions that Clay has been suffering from Dissociative Identity Disorder, which makes him act violently and out of character sometimes, to the point where he's not even aware of his actions.

It's likely that all the guilt that's been weighing on Clay as a result of all the grief he's experienced throughout his high school years, which culminate in Justin succumbing to AIDS and passing away while the two hold hands, sent his psyche into overdrive.

In fact, spray-painting the doors isn't even the only time that Clay acts out of character and dissociates. It turns out that it was also Clay who broke into the school one night and smashed security cameras, and that he was caught on camera setting a car on fire, which led to a dangerous blast. 

Oh, and how could anyone forget the time when he snatched an officer's gun and scared everyone at school?

In short, Clay has some work to do to better his mental state. But it seems like he's finally been putting in the effort, and by the end of the season, he seems ready to set off for a life at Brown University.

Viewers are left with hope after his moving speech at graduation where he addresses all the hardships he's been faced with at Liberty. And when the friends make a pact to always be there for each other if anyone texts "Gordon Lightfoot," it seems they've got their heads on straight.

Binge all four seasons of 13 Reasons Why on Netflix.