old movie. It starred young versions of Dick Van Dyke and Barbara Feldon. I was amazed that I'd never heard of it before, because it started out hilarious, had great actors, and an amusing story line: Dick Van Dyke is a butler and a con-man who defrauds the rich to maintain the illusion that Miss Vicki the woman for whom he's butlering for still has money. He runs a gang of thieves who are all servants in Miss Vicki's household.
The inciting incident occurs when Miss Vicki hires Barbara Feldon as her assistant. Several madcap escapades ensue as Van Dyke tries to keep the truth from Feldon. On top of all that add a large dollop of romantic tension between the two. The conflict ramps up marvelously.
All the while I'm watching it, I kept thinking, "why haven't I ever heard of this movie before?"
Then I saw the third act. Van Dyke fesses up to Feldon and they profess their undying love. OK, then what? Sadly, a tedious final caper. It's tedious because all the air has been let out of the tires. All that delightful tension between Van Dyke and Feldon is replaced with tiresome happiness. Fail. Instead, when Feldon finally figures out what Van Dyke is really up to, an equivalent conflict/tension should have taken its place.
More recently, I watched another movie about a Coca Cola exec adjusting to Australian cultural differences and his attractive secretary. In this story, the conflict comes to a head with just a few strings left dangling--what happened to the girl's dad? This kept my watching closely through the final scene where words appeared to this effect "Then a week later a nuclear war started." What? Where'd that come from? Is this some kind of 1980s Australian political stupid tax? There was nothing to foreshadow that and it had no basis in anything in the movie. Left a bad taste in my mouth. It was like the writer ended the movie and then flipped the bird at the audience.
The last chapters of Neal Stephenson's Cryptonomicon are a disaster because he wraps up too many loose ends too quickly. At each point in the narrative you should ask yourself, "what loose ends are dangling and should I answer these story questions, because bigger story questions are now before the reader?" You should never get to the end of writing The Big Sleep and not know whether the chauffeur was murdered or had killed himself.
A third act fail happens when you start a story with a good premise
with a great deal of promise. But all that potential is squandered when
the 3rd act rolls around. A story has a natural arc and the
characters should be going through changes that are fitting to that arc.
Story questions should be raised and resolved with bigger story
questions raised in turn. Every unresolved story question needs to be
wrapped up. And they can't be wrapped up in a rush.
They say that you should always use the last chapter of your book to sell your next one. That's gospel truth. When I finish a book I feel a certain natural let-down. It's worse when the book ends badly. A 3rd act fail will vaccinate me against ever reading another book by that author. Instead, if the book ended well and left me wanting for more, I'll scour the libraries and booksellers for anything else written by the same author.
Each writer has to worry about maintaining his or her personal brand. I cannot imagine anything s/he might do to damage it worse than a 3rd act fail.