In "Teen Mom 2" Season 6 Episode 12, the season finale that airs Thursday, Leah Messer returns from rehab. Meanwhile, Janelle Evans cannot accept Nathan Griffith's new relationship, Kailyn Lowry threatens Jo Rivera with legal action, and Cole DeBoer moves in with Chelsea Houska.

Messer looks well, but is still battling anxiety about dealing with her ex-husband Corey Simms.

In the video clip, Messer is driving with her cousin Chastity and friend Brianna to meet Simms at a restaurant to discuss their daughters Aleeah and Ali.

"I'm just so nervous. I hope I'm ready for this conversation," she says while driving on the highway.

Messer parks at the restaurant. They spot Simms' car.

"Alright, good luck," Chastity says, but then sees Simms' wife Miranda sitting at another table and adds, "Why is she there? She is sitting right there. Why can't she sit in the car?"

Messer looks concerned.

"I'm not doing the conversation if Miranda is here," she says, and the video ends.

Also, Griffith arrives at Evans' house wanting to make peace, after she was arrested for attacking him when he brought his new girlfriend to pick up their son Kaiser.

"Obviously, I would not be over here if I did not still care about you," he says, as they sit on the couch together. "Um, we do need a new game plan to stop the fighting, stop the feuding, stop all the madness and violence --"

Evans interrupts him and says, "So, why did you go to the police?"

Griffith points out he never pressed charges.

"It said that you walked in and you said that I attacked you. It said that you showed them the marks on you," Evans says, referring to the police report.

He says that the police took pictures of the marks, which is how they knew about them. He wanted a temporary restraining order until she calmed down.

Her eyebrows raise.

"Until I calm down? How am I supposed to remain calm if you bring that girl to pick up Kaiser? I'm just sayin'. You'd freak out, too," she says.

Griffith looks exasperated that his efforts to make peace aren't working.

"Anyways, we need to come up with a game plan. I want to move forward. I care about you. I'm done fighting with you," he says.

Evans asks, if that's true, why he has the new girlfriend in his life.

"Now you're going to get upset -- because she's an awesome girl," Griffith says.

Meanwhile, Lowry confronts Jo Rivera at his house about forgetting their son Isaac's games, graduation and life events. Rivera becomes defensive, saying that he is tired of arguing with her over petty things. He calls her names as she pushes the issue.

Lowry warns Rivera that he needs to do better with Isaac if he expects favors from her, which angers him more. The favor she refers to is allowing him to pay child support without a court order.

Rivera claims her doing so helps them both because he can't pay more than he has. It's a struggle for him to take care of himself, he says.

"You're about to have a baby so you better get it together," Lowry tells him.

Meanwhile, DeBoer moves in with Houska and her daughter Aubree, who is super-excited about having him in the house.

"He's mine!" Aubree shouts while sitting on his lap.

She also tells him that he has to keep the toilet seat down.

Watch the "Teen Mom 2" Season 6 finale on Thursday at 10 p.m. EDT on MTV.

Do you think Corey's wife Miranda has a right to be at Leah's meeting with him? Do you think Jenelle will ever accept Nathan dating other women? Is Kailyn wrong to threaten taking Jo to court for child support? Share your thoughts in the comment section below.