In this episode titled "The Persistence of Memory" Regina encourages Kathryn to learn Daphne's language and get to know her in a whole new way. A little while later Kathryn knocks on the door and signs to Regina that she wants to learn. Endearingly, she is nervous that she has signed wrong as she explains that she learned how to sign that much off the internet. Regina responds graciously telling her she could understand her and that it will mean a great deal to Daphne.
That was probably my favorite moment of the whole season so far.
If you're watching the show, what do you think of how the story lines have developed?