Center of the World #TheScarletLetter

With their landlady pressing them to pick a new housemate soon, the Belle Epoque quartet has no other choice but to lower their standards ... a lot.

As Eun-jae and Ye-eun try to cope with the stresses of a new semester, Ji-won is still her usual perky self, but something keeps troubling her.

Returning home and finding a strange man in their bathroom, Ji-won, Ye-eun and Eun-jae panic, but it's Jo Eun who seems especially traumatized.

As Jo Eun struggles to define her friendship with Ye-ji, Eun-jae frantically searches for a way to undo the message she sent to Jong-yeol by accident.

Ye-eun teaches the housemates tricks to win over guys' hearts, which Ji-won uses on Sung-min to make him join her quest to recover her lost memories.

Suspecting Kwon Ho-chang to be the sender of the unpleasant text message, Ye-eun enlists Ji-won's help in figuring out what kind of person he is.

After hearing the alarming news about Ye-eun's ex-boyfriend from her lawyer, the housemates remind one another to be extra careful from now on.

Ye-eun is certain the letter is meant for her. Ji-won, Eun-jae and Jo Eun visit the bookstore to find the owner of the book that contained the letter.

As the housemates fail to console Ye-eun, help comes from I-na, who makes a surprise visit. I-na also sheds light on where the pink letter is from.

The unidentified assailant demands to know why the housemates came looking for "Joanne" and provides a crucial piece of information about the letter.

Using Ji-won as an excuse, Jin-myung convinces the housemates to go apple picking. But in fact, everyone -- not just Ji-won -- needs a little break.

The housemates surprise Eun-jae with a small party when she returns from meeting with Jong-yeol. Ji-won visits her elementary school art teacher.

All the pieces of Ji-won's childhood memory finally come together. Meanwhile, Jin-myung stresses over keeping the "promise" she made to Heimdal.