OK, you've all seen it. The monster -- whatever it is -- lumbers, shambles along at a pace that could barely be called a saunter. Even Grandma Walton could outrun Mister Leisurely. In addition to being as slow as molasses in January, he's usually fairly clumsy to boot. Yet he consistently chases down, corners, and slays victims thoughout the book, comic, or movie. How does he manage to do that?
Another chestnut at least as old as the pulps: Mr. Rich Guy, knowing he's in danger, locks himself in his interminable, shadowy mansion, zealously guarded by his servants and perhaps the police. They make the rounds regularly, ensuring that all the doors and windows stay sealed. They search the house repeatedly, finding no strangers and no sign of entry, forced or otherwise. Yet at the Hour of Doom, Rich Guy looks up from his massive mahogany desk to see the killer standing in his study mere paces away. It can't be supernatural, because even Batman villains can do it. How'd the monster manage to do that?
If you have answers, or a beef with a favorite suspense/horror trope, feel free to jump in.