Nick tells fellow vampire Aristotle, "You still owe me for that time at the Battle of Hastings." Nick was brought across in 1228, or so the intro told us every week. The Battle of Hastings, as any British school kid knows, was fought in 1066, over 100 years before Nick's mortal birth.
All the sets in the dream sequence, particularly Nick's loft, are filled with props referencing Lewis Carroll's Alice in Wonderland books. They include white rabbits, flamingos, walruses, a squeaky-toy caterpillar - even a half-eaten piece of cake in Nick's fridge. The episode also has several background extras in Wonderland-style costumes, and numerous other references to the books, such as Nick literally falling through the looking glass at the end.