Last night’s episode of Mr. Robot, the first in a two-part finale, took us on a dreamy journey full of Back to the Future references and a real-but-not-quite-real adventure, marked by a loss of control and an unwieldy grasp of reality. A not-so-subtle hint at the beginning of the episode suggests that it largely consisted of a lucid dream.

When we see Angela in the back of the van or in the room with the Whiterose and the slowly draining fish tank, our view of the world in which she exists is shrouded; it feels real, but oddly incomplete. Though her surroundings are presented in fine, real-world detail, they don’t feel lived in so much as they feel created. We get the sense that they’re being influenced by someone’s imperfect subconscious.

Lucid dreaming is a type of dream state wherein dreamers, existing in a semi-aware state, can do this. In this case, our dreamers are Elliot and Angela, and they have access to cognitive tools, allowing them to take control over their actions and their surroundings. The brain activity of lucid dreamers shows that they’re at least partially awake, so they’re thought to be in a state that exists between REM sleep and wakefulness.

Lucid dreams aren’t especially uncommon, and there large groups of people who are devoted to experiencing and understanding lucid dreaming. But just as dream experiences vary greatly from person to person, lucid dreaming isn’t the same for everyone. The idea comes back to influencing and controlling the contents of your dreams, whether for pleasure (like flying dreams, for example) or for surprisingly practical purposes, like solving real-world problems in a different context without real-world consequences.

This episode of Mr. Robot includes many odd references to Back to the Future (right down to the music), and vast portions of Elliot and Angela’s experiences seem surreal and ungrounded in reality in the just-slightly-off way that realistic dreams often are. Like most of Mr. Robot, what we see isn’t always what’s real, but it’s almost always of consequence. Through the lens of lucid dreaming, we see that plenty of things that happen in Mr. Robot don’t belong in the real world — at least, not in the strictest sense — but that doesn’t mean they’re not real enough to have an impact.

Photos via USA Network