Here is the text of "Pickman's Model," one of HP Lovecraft's classic stories. I love it. I think it delivers that frission you expect from Lovecraft, which comes from the realization that there is another, darker world just beyond this one. And sometimes its inhabitants pay us a visit.
Now, below is an adaptation of the story from the second season of Rod Serling's Night Gallery. You can watch it if you want, but it's awful. I think it's entertainingly bad, and certainly worth a viewing. But you've been warned.
The episode is bad for some of the obvious reasons. It's just standard mediocre TV type stuff. But what makes it truly disappointing is Pickman's paintings themselves... as well as the guy in the rubber suit at the end. And that's where Serling does us a favor. The crappiness of the show actually reveals something about horror. It shows us that there are some monsters which can never be shown.
"Pickman's Model" is structured much like Poe's "The Tell-Tale Heart", where a narrator is speaking to us as if we are a character engaged in a dialogue with him. It's a weird framing device, and both authors use it to make us unsure of what to believe. "Pickman's" narrator is describing his encounter with a group of paintings that were so terrifying they made him scream out loud. As readers we're incredulous. But he seems sincere and level-headed, and as he explores Pickman's studio he sees and hears things which even he admits he's unsure of. Because we're removed from the action, we feel this great tension. What the hell just happened? Poe's narrator might actually be crazy -- he comes right out and says so in the very first sentence -- and his horrifying encounter might be an auditory hallucination, or it might be some kind of supernatural phenomena.
In both cases part of the horror comes from the uncertainty of dealing with other people. We spend our lives telling each other stories, transmitting information. And each story is like a flashlight shining in a dark room. I am showing you something, but you know deep down that there's much you can't see. And of course I could be mad, or lying, or carefully shading the truth for some reason only I know. Seeing Pickman's monster is not the point. It is doubting the tale-teller, and feeling a little of the paranoia that is the background noise in every conversation you've ever had... Because while you're fumbling around in that dark room, I might just turn out the light.