Four of Ritchie's college students (because of course, college students) steal the diary of Jacob Shaw from his collection for their seance. Shaw, as it turns out, was an expert in astral projection who created another world as his personal afterlife. When the four students conduct the seance, they unintentionally wander into Shaw's home and realize he's far less stable than when he was alive. The weekend practitioners are able to escape back to their bodies, but they also leave the gateway to Shaw's world open. That means if they spot Shaw's image in a mirror, he can drag their souls back, murder them, and leave their empty shells in the physical world.
These are the biggest metaphysical concepts Constantine has ever put forward, and they're used to recreate Scream and I Know What You Did Last Summer. While Constantine and Ritchie stumble around trying to find answers, these scared students are picked off one by one, all while using bad movie logic to deny the reality of what's happening to them. And I'm not exaggerating with the slasher bit either - once they're in his world, Shaw needs to kill them to trap their souls, and stabbing implements are his weapons of choice. Despite literally being the god of his little world.
The first half of the episode is almost a wash, except for one elevating factor - Shaw's world reflects John and Ritchie's Personal struggles. Ritchie literally fantasizes about being plugged into the technological singularity so his consciousness can be kept apart from the world's dangers. And John just wants to get back his safe house world and drink until he forgets his troubles. These men are both just as damaged by magic as Shaw once was, even though neither of them went over the edge. There are layers of depth and foreshadowing that actually elevates the generic slasher tone somehow. But don't be fooled - half the episode is still a very generic slasher.
Thankfully things shift gears in the second half of the episode, and the parallel dimension concept more fully comes into view. Shaw has claimed all of his souls except for that of "The Last Girl" (because of course) but now Constantine and Ritchie have a plan - make the leap into Shaw's dimension for a final showdown. I'll admit it's like switching from Friday the 13th to Nightmare on Elm Street, but it's a far better fit for Constantine's world. Shaw's universe is a house constructed from his psychic landscape, filled with dead ends and mutilated victims. It's a great place for a psychic showdown, and even though the twists are predictable, they're entertaining to follow. This is also apparently where Constantine sunk a portion of its visuals budget, creating a final sequence that actually takes on an otherworldly feel.
After a rocky beginning, "A Whole World Out There" ends on a great note, especially thanks to what it reveals about John Constantine. Shaw's world is one of those dream spaces where believing in yourself actually creates change, an ability we see expressed in Ritchie and one of his students. What's interesting, however, is that Constantine does not express this ability. After all these victories, John Constantine may actually have very little faith in himself, and can only manipulate others into doing the right thing. It's never quite put into words, but couldn't be more clear when Ritchie finds the answers he seeks, while John goes right back to the bottle he started from.
Even though he hasn't changed, we've actually learned a lot more about Constantine's character than most previous episodes. That's very impressive, slasher premise or not.
Bottom Line: "A Whole World Out There" is what happens when Constantine combines slasher tropes with mind-bending concepts about psychic landscape. Sadly, the end result isn't quite as cohesive as it probably sounded in theory, but it still manages to stand out in ways few other episodes have achieved. That doesn't make it as good as recent episodes, but it's certainly fun to watch.
Recommended: This is an episode you could skip, but it's also the most vulnerable performance we've seen from Matt Ryan's Constantine to date. If you don't mind the slasher film logic, it's worth it for that alone.