I was so ready to have nightmares from this episode.
One-off scary episodes are what Steven Moffat does best. There are no long-term plots to manage, or emotional arcs to develop. The episodes don't even have to be internally consistent. They just have to be absorbingly, atmospherically creepy, playing on subconscious childhood fears. It's small scale, deeply focussed, characters-in-the-basement-while-the-light-flickers stuff. We don't have to know or care about anything beyond this particular moment and how terrifying it is.
Which is why Listen only half-worked. Half of the episode is about hiding under the bed while an unseen monster may or may not lurk in the room, while half of the episode attempted to go grand scale, confusing-character-timeline, big picture story. And the two halves just didn't click.
Not that the problem was the story's resolution, or the fact that the monster was never real. These super-scary Moffat episodes are always psychological to some extent, so it's actually an interesting twist that there was no monster at the end, that it was actually just the Doctor's childhood fear. The resolution doesn't affect how scary or un-scary the episode was up to that point, and after many similar episodes of real monsters, it's a twist that I don't think most people will have expected. It's also a twist that doesn't quite answer all of our questions. Yes, Clara accidentally motivated the Doctor to obsess over and research this fear, but it doesn't mean his research or his fear is wrong. It doesn't mean that there wasn't a monster in Rupert's room, especially as we saw a blurry glimpse of something that did not look entirely human in that scene.
At least, I think it didn't look entirely human. I was too busy peering through my fingers to be sure.
With better execution, this could have been the best episode of Doctor Who in years. But that execution fell apart entirely in the second half, simply because it wasn't satisfied with being small. It didn't stay with nighttime fears in a children's home, with a strange figure under a blanket that you promise not to look at. It wanted to be a bigger story, so it took us to the end of the universe. It took us back into the Doctor's childhood. It showed us Clara's potential descendant, a time-traveller trapped in the universe's final moments. And so suddenly, it was no longer scary, because it was no longer relatable.
Sure, we can all identify with hearing strange noises and being afraid that something is causing them. But I'm not sure many of us can identify with hearing strange noises outside the airlock at the end of the universe, or seeing the airlock door turn by itself. Strange noises from the next room while we're in bed? Yes, that's terrifying. But strange noises in a completely imaginary and unrelatable situation? Suddenly it's fantasy scary, not real life scary, and that's not really scary at all. It's not something that will have us turning on the light at night or make us afraid to step out of bed, because there can be no little voice in the back of our head thinking it might be true. There might be something there. It's a monster at the end of the universe, not a monster in our dark houses. The moment that monster is put in a fantasy adventure context, the episode loses its power, even if it had us terrified five minutes before.
The episode's other problem was it simply got messy. We had good acting and good lines from both the Doctor and Clara, but there was simply too much going on that was unrelated to these potential monsters. Too much jumping about in time, too much worry about Clara's date, too much weirdness with Orson Pink and Clara's future. It was simply too much, too big, when the scary factor actually comes from from really small, zoomed in moments, where it's just a character, the dark, and a monster they can't see.