Anticipation Stage and "Fall" into the Other World
A Connecticut Yankee in King Arthur's Court follows a Voyage and Return plot, as discussed by Christopher Booker. However, Twain is also writing a satire, so he up-ends a lot of established conventions while still sticking to the basic structure. In many cases, the hero in these stories is young and inexperienced, eager for adventure or otherwise in need of a big change in their world. Hank is the exact opposite, though: experienced, worldly, happy with his lot, and not at all in need of a blow to the noggin to send him off to a magical land of enchantment.
Initial Fascination or Dream Stage
Stories of this kind typically entail a period of wonder as the hero explores his new surroundings, but not so much for our dear Hank the Yank. Yes, he's in a new world, but it's mucky and gross. He's taken prisoner, scheduled to be executed, and forced to endure the slovenly table manners of the so-called nobility. The only wonder he experiences is realizing how dim these people are, and figuring out how he can turn that to his advantage.
Again Twain sticks to the basic structure of the Voyage and Return plot while overturning the effect this stage has on the story. Hank faces a series of challenges as he goes through the medieval world, but they don't seem to bother him much. Instead, each time he manages to come up with a new solution that puts him in an even better position. His frustrations mainly stem from an inability to get other people to understand his ideas, instead of any real challenges or threats.
The nightmare stage, in this case, arrives suddenly and without warning. Instead of a gradual build-up, it comes at Hank the Yank in a great rush: Arthur dies, the kingdom turns against him, dogs and cats start living together… okay, not so much with that last bit, but you catch the drift. Even here though, Twain defies our expectations. Hank and his friends have planned for the worst, you see, and turn their supposed defeat into an against-all-odds last stand for the ages.
Thrilling Escape and Return
Like the rest of the book, the return to modern times—courtesy of Merlin's spell—is actually a quite unhappy ending for Hank. Instead of returning with hard-won wisdom and maturity, he's ripped away from everything he loves and saddled with the knowledge that all his positive changes to the past have been wiped out. It's a pretty rough ending for a comedy, but so it goes with Twain.