There's a disappointing truth to Death House—the prologue to Curse of Strahd—and it's that it's alternative ending "The Cult is Denied" is just a dull series of rolls. Each character rolls against poisonous smoke. Each character rolls to pass through the scythes. While frightening at first, it quickly loses its charm.
Enter the Skill Challenge: Escaping Death House.
This guide provides a skill challenge as an alternative to the "Cult is Denied" ending. Utilizing—my god, the horror!—their skill proficiencies, the players must achieve five successes before accruing three failures lest they never escape the nightmarish halls of Death House.
If you've never ran a skill challenge before, don't fret. The concepts and rules are explained, and a Frequently Asked Questions section is provided at the end of the module.