Anyone reading this webcomic? If not, you probably should be. The series falls into the genre of magical British boarding school fiction, but adds interesting layer upon layer to develop a complex mythology. One of the most fun aspects, however, is the use of long setups that take weeks, months or years to payoff - and boy do they pay off.
The current storyline involves main character (and partially magical being) Annie and her more practically minded scientist best friend Kat traveling into the Realm of the Dead to learn the secrets of a powerful ghost they've tangled with in the past. Readers are presented with dollar store Halloween props, plastic bats, cheesy costumes and paper skulls and told, very bold-faced, that this is an arcane world of mystery. It readily becomes apparent that we are seeing the RotD through Kat's eyes, and that Annie is seeing something altogether more horrifying. The punchline doesn't drop for over 20 pages - one page published every other weekday - but it's worth the wait.
Another one, highly recommended even if you've never read this comic, involves the origin of Jones, an enigmatic emotionless and apparently indestructible woman who appeared on the strip several years prior. Her story is perhaps the most epic single character origin story I have ever read - and that is saying something.