Hanna had all intentions of confessing to Wilden’s murder, in hopes of getting her mother, Ms. Ashley Marin, out of jail. In Season 4, Episode 8, titled "The Guilty Girl's Handbook," Hanna decided to invite Mona over to hatch a plan to confess to the murder.

Previously, Hanna received a call from Ashley in jail who tried to assure her that everything would be OK. However, Hanna felt that confessing to murder was the only option. And what better person to help you fool the police than Mona?

Caleb arrives at Hanna’s home and is immediately asked to leave at Hanna’s request. However, Caleb doesn’t trust Mona as far as he could throw her, and he sticks around. Once Hanna realizes that Caleb is still around, she tells him her plan.

Although Caleb gets immediately upset and forbids Hanna to confess, she’s set on taking her mom’s place. Hanna later heads over to Spencer's, and the ladies learn from Ashley’s lawyer and Spencer’s mom, Veronica Hastings, that someone has confessed to Wilden’s murder.

As the liars and their mates head to the police precinct, they discover that Mona has decided to take the fall. Hanna never gets the opportunity to confess.

Mona took action because she still loves Hanna despite putting her and the other liars through hell. Not to mention, Mona has always had a soft spot for Ms. Marin. And of course, Mona’s confession sparks reasonable doubt about Ms. Marin’s involvement in Wilden's murder, which allows her to be released on house arrest pending trial.

Thankfully, the trial never happens due to a witness — Hannah’s old fling, Travis — sharing with police that he saw Ms. Marin driving away from the lake when gunshots rang out and Wilden was murdered.

Now, even though the book is officially closed on PLL, fans are hoping that the spinoff doesn’t disappoint.

You can watch the original Pretty Little Liars series on HBO Max; Pretty Little Liars: Original Sin premieres on the platform on July 28, 2022.