The HBO series works the same way, and "Dissonance Theory" is a prime example. To unpack Westworld's mystery box, you have to admire the wrapping paper, then tear through it for the surprise. The gift in "Dissonance Theory" is Dolores' moment in Las Mudas.
Dolores appears in the faux border town shortly after waking up near the doting William, picking up where Episode 3 left off. She investigates the fountain in the town's main square. Wood gives this surreal sequence an air of familiarity as the camera spirals around her. And with a whoosh -- or perhaps the sound of a rumbling storm? -- a young girl appears next to her.
We've seen this foreboding young host before, of course -- she's the daughter of Clifton Collins Jr.'s Lawrence, the child who informed the Man in Black that the maze "isn't meant for you" and told him to "follow the blood arroyo to where the snake lays its eggs." She pops up again and helps trigger a memory (vision?) buried in Dolores' cortex.