The Big Bad Wolf invaded Storybrooke last episode on Once Upon a Time, but viewers should prepare themselves for an even scarier creature on this Sunday's "Heart of Darkness."
Big, bad, brainwashed Snow White.
In fairytale land, look for Charming to do all he can to prevent his unhinged love from assassinating the Evil Queen; while Mary Margaret is in trouble of her own in the real world. She'll hire Mr. Gold as her attorney after Emma is forced to arrest her on suspicion of murder.
Get your first looks at what's to come via the following preview and sneak peek.