Answer:
The excerpt presented allows readers to approach a “forbidden door".
Explanation:
In "Danse Macabre", Stephen King describes how society influences the horror genre. Be it in books, comics, films, etc. He explores the history of the genre and how real life situations are the consequence of that history.
In this case, King is pointing us to a "forbidden door".
"(...) he peered into the darkness."
"(...) he could resolve this mystery. He swung his legs to the floor with conviction."
The character is going into the darnkess to solve that mistery. He is going to cross that "forbidden door".
