" Adam and Kristina have a health scare while Crosby and Jasmine celebrate their first Christmas together as a family. Sarah has mixed feelings and is torn between Mark and Hank. Amber and Ryan's relationship faces some challenges. Zeek helps to restore belief in a childhood hero. "

Has this been the most rewarding season of the show for you so far?

Yeah, I mean last season was really great, too, and Lauren and I got to work on the conflicts of being a new couple. But this is the first time that there's been a real big threat and Mark's had to stand up for himself. Last season, Seth came back, but Mark sort of backed off and let her handle it. This is a new and active threat, and so it's been really fun and we get to see a little bit more of Mark's personality. When you move in with someone, there are a lot less places to hide away, so some of the darker stuff does come out and it's been a lot of fun.