"Psych" star Maggie Lawson will join the cast of "Two and a Half Men" when the long-running comedy series kicks off its 12th and final season this fall.

Earlier this summer, CBS Entertainment President Nina Tassler revealed that Walden and Alan will agree to adopt a child after Walden suffers from a health scare that causes him to re-evaluate his life. However, in order to do so, the heterosexual roommates will first have to get married since its easier for married couples to adopt.

That's where Lawson's character will come in. Lawson, who recently starred in the comedy pilot "Save The Date" on CBS, has been cast in a recurring role as a social worker who will help the duo, reports Deadline.

Tassler dropped other spoilers about the same-sex wedding next season, telling The Wrap that "Walden has a near-death experience" which "forces him into sort of this existential quandary and to evaluate the meaning of his life, the quality of his life, which prompts him to say, 'I need to put down deeper roots.' And he wants to adopt a child."

Tassler went on to explain that Walden, who is single, believes it will be easier for him to adopt if he were married.

"He wants to adopt a child and it is particularly challenging to do so as a single male. So he decides that he and Alan should get married, and they will adopt a child as a gay couple," she teased during the Television Critics Association summer press tour in July, according to ABC News.

When asked if she expects the plot to stir up controversy, she responded, saying, "It's going to engage people who perhaps have not wanted to be part of this conversation before. The reality is it is legal, same-sex marriage, and it is legal for you to adopt a child and that's what they're doing and they're doing it in a very public forum. It's a ruse, but the reality is it is legal and it may engage viewers who haven't necessarily wanted to talk about it before and people will be talking about it."

Season 12 of "Two and a Half Men" premieres on CBS on Oct. 30.