[This is a review of Penny Dreadful season 1, episode 5. There will be SPOILERS.]

Now this is how you do a standalone episode. ‘Closer Than Sisters’ doesn’t just function as an immensely satisfying flashback with its own beginning, middle and end, but it also manages to have a major effect on Penny Dreadful’s main mission without ever even touching the present events.

Eva Green continues to prove she can carry a show all on her own by exhibiting astounding range throughout the episode. We begin with Lili Davies’ young Vanessa who naturally exudes happiness only to have her pure joy corrupted by catching her mother and her best friend’s father, Sir Malcolm, in the act. Then, with a rather delicate tonal shift in the score and Green’s profound narration, you can see and feel feel the darkness start to slip in.

From there, what Green does with Vanessa’s innate kindness and that growing darkness is nothing short of astounding. She effortlessly sells a younger, innocent version of her character before deftly letting the inner demons take hold. Even though Vanessa harbors malicious intentions and ultimately carries out a particularly cruel one, not for a second do you ever doubt her adoration for Mina (Olivia Llewellyn).

You’ve got this woman who’s been best friends with the same person for years and truly only wants the best for her, and yet she has absolutely no problem sleeping with her husband-to-be the night before their wedding. If anything makes you doubt Vanessa’s integrity, that should be it.

But by planting the seed with her mother’s infidelity, explaining why Vanessa stole from Mina when they were children, showing the failed kiss with Peter, slipping in dialogue like, “God, how I envied you. Perhaps I even hated you,” and topping it all off with hints that there’s an evil entity in the mix, you can’t help but empathize with her. She did a terrible thing, but it wasn’t entirely her fault.

Once Vanessa’s illness sets in and she makes her way to the asylum, things get especially disturbing. On the one hand, we’ve seen the good in Vanessa, so it’s crushing to see her endure such a torturous form of treatment, but then we’ve got moments like the one in Dr. Banning’s (Frank McCusker) office. Whether it’s her fault or not, Vanessa is dangerous.

There is relief that comes with seeing Vanessa back at home in a proper bed, but there’s also an astonishing amount of unease and dread. Vanessa is practically immobile during her conversation with Peter (Graham Butler) before he leaves for Africa, but their proximity – and the fact that Vanessa isn’t in full control – makes the moment extremely tense.

And after all that, she doesn’t even do anything. Here’s this character you’ve come to know and trust throughout the show, and in this very moment, you expect her to jump up and attack someone she loves. When she doesn’t, it’s hard not to feel guilty over losing our faith in her. She’s being manipulated by a dark force and, it turns out, so are we.

But just before you can get back to siding with Vanessa and her cause, her inner demon arrives to prove she started it all. “You’ve always been drawn to the deep ocean, to the dark whisper, the mirror behind the glass eyes, to life at its fullest. Can you close that door now?” And the answer is no.

‘Closer Than Sisters’ almost entirely changes the way we view Vanessa, and not in a straightforward manner. It doesn’t make us pity her for having a difficult youth and it doesn’t offer a finite twist branding her a villain either, but rather leaves us juggling both versions.

Vanessa is clearly capable of giving into evil, but that final conversation with Sir Malcolm and the passion in her letter suggest that her purpose is truly to right her wrongs and save Mina, even if her definition of “save” isn’t in line with Sir Malcolm’s.

Penny Dreadful continues next Sunday with ‘What Death Can Join Together’ at @ 10pm on Showtime.

Follow Perri on Twitter @PNemiroff.