The Old Switcheroo, Part 1
When last we saw Mara she'd just realized that Audrey was still alive inside of her and had vowed to kill her off. Since Dwight, Duke and Nathan don't know any other way to bring Audrey's personality out, they keep talking to Mara as if she is Audrey.
When that doesn't work, Nathan decides to do the unthinkable: Take Mara out on a case. Working cases is something that Audrey loved to do, so Nathan hopes that Audrey will find a way to assert herself through the casework. Now all they need is a Trouble. They get one soon enough when Dave and Vince end up switching bodies. In a matter of moments, Dave comes to inhabit Vince's body and vice versa.
This new Trouble spreads quickly and, soon enough, Dwight and Gloria end up trading bodies too. Eventually, Nathan is able to figure out that keeping a secret from someone close to you is what triggers the Trouble. In fact, when Nathan leaves Duke alone with Mara, Audrey's personality comes out and she brings up the kiss she and Duke shared in Colorado—a secret Duke never shared with Nathan. Almost instantly, Duke and Nathan switch bodies.
Nathan (now occupying Duke's body) is dismayed by the news that Audrey and Duke kissed but he doesn't have much time to think about it before Duke (now occupying Nathan's body) calls to tell him an even more startling truth: Mara is using Audrey's memories and pretending to be Audrey so that she can escape.
Duke comes to this conclusion because he remembers that the kiss he shared with Audrey wasn't much of anything to either of them but now, Audrey seems to be building it up as a big deal. That and the fact that she keeps asking for her shackles to be removed is proof enough for Duke.
Meanwhile, Dave (in Vince's body) has followed Vince (in Dave's body) to Mateo, North Carolina where Dave was attempting to chase down his past as an adopted child before the body switch. The two of them work together to find the home listed in Dave's adoption paperwork but it seems like a dead end until they discover that someone in that family's home has been calling Haven.
That's not the only thing they discover. It also turns out that the home in Dave's adoption papers also happens to be the location of a "thinny," which tries to pull Dave back into the dimension where William lives. Luckily, Vince is there to stop him. *Sigh of relief. *