The quick one-paragraph High Concept: Girl Genius is set in the world where Mad Science is real. A small number of Mad Scientists, or "Sparks", have the ability to invent -- well, more or less anything. Needless to say, history took a left turn at Albuquerque, and kept going all the way to Hawaii. Our heroine, Agatha Clay, is a lowly lab assistant at Transylvania Polygnostic University when the story starts. Things get more complicated from there, very quickly. The story is sprawling, messy, and loads of fun, in a world whose complexities have barely been scratched so far. It's broadly humorous, but always with a serious undertone that keeps it from simple goofiness.
Spread the word. Girl Genius is my A-number-1 favorite comic (this from the guy who buys half the comics out there), and I would like to see this online experiment succeed. They make no bones that it's a loss-leader for the paper collections, and I encourage folks to pick up those collections if you don't have them already -- they're well worthwhile. But first, check out the story online. ("Have some candy, child...")