It's approximately half a year after the Changling siege on Canterlot, and everything seemed fine and dandy, but for unknown reasons, Rainbow Dash goes missing for a full month. But when she came back, she wasn't exactly the same…
In other words….

"Sun shines, Grass grows, Birds fly, and buddy…I hurt ponies!"

(Warning, the following story contains insults, sometimes strong language, flirtation between two mares, skull fracturing, baseballs to the knee, excessive drinking of radiation in a can, and just pure awesomeness altogether, you have been warned…)