Credit: Jonathan Hession/SHOWTIME

Showtime’s new horror series Penny Dreadful just keeps getting better and better. After the awesomeness that was Season 1, Episode 3 (“Resurrection”), things will definitely be heating up this week with Season 1, Episode 4 (“Demimonde”). What happens during Sunday night’s episode? Read on to find out!

First thing’s first, what does “demimonde” even mean? According to Merriam-Webster, the word means “a class of women on the fringes of respectable society supported by wealthy lovers,” or, simply, “the world of prostitution.” In fact, the origin of the word is around 1855, which puts it right around the time Penny Dreadful is set. Or, if you’d rather hear it explained by an amazing actress, see here.

Given the fact that Vanessa Ives (Eva Green) and Brona Croft (Billie Piper) are the only female characters featured prominently on the show (thus far), we’re going to take a gamble and say the episode might reveal more about Brona — perhaps confirming that she is a lady of the night?

Check out the full synopsis for the June 1 episode:

“Vanessa’s infatuation with Dorian Gray (Reeve Carney) continues to grow. Professor Abraham Van Helsing (David Warner) is hired by Sir Malcolm (Timothy Dalton) to work with Dr. Frankenstein (Harry Treadaway) to uncover a cure to the disease that might be affecting his daughter. Fenton (Olly Alexander) draws his master to Sir Malcolm’s mansion.”

What do you think is going to go down in this week’s episode? Hit the comments and speculate!

Penny Dreadful airs Sunday nights at 10 p.m. ET on Showtime.

Carson Blackwelder is an Assistant Editor at Wetpaint Entertainment. Follow him on Twitter and Google+!