In the final FINAL episode of Season 4, Stephen and Mark become so enamored with 2XO Bourbon from the last episode, they decide to make Old Fashioneds with it and completely forget to talk about what they forgot to talk about in "The Halloween Tree" by Ray Bradbury.  Witness the chaos as the boys fall down the cocktail rabbit hole as they decide to try to invent their own cocktails.  Maybe they're just tired.  Maybe it's been a long season.  Maybe the 2XO is just that good.