After confessing to Stef (Teri Polo) and Lena (Sherri Saum) that she slept with Brandon (David Lambert) before her adoption was final, she went into a brief downward spiral of acting out -- punching classmates, running off with strangers from coffee shops -- as if she was trying to prove she isn't worthy of a family. The same thing happened in Season 1 after she and Brandon kissed for the first time, and in Season 2 when her biological father Robert (Kerr Smith) tried to block her adoption.
"When she doesn't feel like she's in control or when she feels like something being taken away from her, she does something to take it away herself so she can at least be in charge of her own future and what's going to happen to her," Mitchell explains to TVGuide.com "She is now kind of understanding it more and these are some deep, deep patterns that she's had."
This time, Callie's self-destructive pattern may have finally lead to a redemption arc that will not only put her back in Stef and Lena's good graces, but help her gain the confidence and trust she needs to believe that she's loved by her family. In Monday's episode, titled "Now for Then," Callie begins a photo essay about the seven homes she's lived in over the past seven years. The project leads her to find out her former foster brother Kyle is serving a life sentence for a murder Callie doesn't believe he could have committed.
Callie will take up arms for Kyle and devote herself to trying to find some justice for a boy she only remembers as kind and quiet, which will help her reconnect with her family along the way. "I think she and Steph kind of connect over it as well because Steph's a cop," Mitchell says. "Steph is quite inspired by it. [Callie] definitely, through all of it, has the foundation of having this permanent situation where she [feels] like she can go and help other people now because she's got that consistency for herself. So it definitely helps her feel like she's safe to do so and also makes her appreciate it."
However, as things get better between Callie and her moms, the case will reconnect her with Aaron (Elliot Fletcher). The college-age law student Callie met in the coffee shop last week and kissed on the beach will help her try and prove Kyle's innocence -- but also cause some waves between her and her boyfriend A.J. (Tom Williamson).
"[Callie and Aaron] kissed and they're both young people and spending a lot of time together, but she's in this quite serious relationship with A.J.," Mitchell says. "You see her relationship with A.J. definitely tested because of it." And that day at the beach will definitely come back to haunt Callie. "That's going to be a whole thing. It's not just ignored and swept under the rug," the actress promises.
Boyfriend drama won't get her kicked out of her forever-home though, and that will be the most important thing Callie takes away from this arc. "It's about trusting love and trusting consistency and trusting that the people around her aren't going to give up on her if she messes up," Mitchell says. "...I think doing the worst thing that she could have done, which was for her and Brandon have sex, and then for the parents to find out and then still accept her... I think that really was exactly what she needed to feel like she had a permanent situation because even when they adopted her I don't think she felt that way."
The Fosters continues Monday nights at 8/7c on Freeform.