Harry's sister, Kate, makes a surprise appearance in the news of Joss and Harry's engagement, but she comes with her own secrets, and her on troubles, on Mistresses Season 4 Episode 2.

Meanwhile, Karen continues her book launch with her new agent, Barbara (guest star Tia Mowry) while sparks continues to fly between her and her new manny. Will Karen give in to him, or will she keep their relationship strictly professional?

Will Karen's strong personality clash with Barbara's over the details of her launch?

Kate is bound to stir up trouble, but how much? And what could she be hiding?

How will she react to her brother marrying his ex-sister-in-law?

You can watch Mistresses online in case you missed the season premiere, or if you want to revisit Kate's first appearance in Mistresses Season 2.

1. The New Mistress - Mistresses Season 4 Episode 2

Kate comes to town looking for trouble. Will she be a good fit with the other ladies? She is the new mistress, after all, taking Calista's place.

2. Sisterly Love - Mistresses Season 4 Episode 2

Kate's sudden arrival seems to be welcomed nicely, but why did she randomly show up at Harry's door? Does she have a secret?

3. Friends or Foes? - Mistresses Season 4 Episode 2

Joss and Kate seem to be getting along, but could Kate cause problems between Joss and Harry? After all, she is Savi's sister, and it's doubtful that sat well with his family.

4. Uh Oh, Joss - Mistresses Season 4 Episode 2

Joss doesn't seem to be taking whatever Kate is telling her lightly. Something important, or something scandalous?

5. Who Is This? - Mistresses Season 4 Episode 2

Who could Joss be talking too? Whatever it is, it doesn't look very comfortable for her. Maybe a message from Savi? Doubtful, but one can only hope.

6. I Have Big Plans For You - Mistresses Season 4 Episode 2

Now that Karen has an agent promoting her book, and eventually second book, what does Barbara have in store for her? She looks like she has everything figured out.