From the publisher:
This adventure presents four linked encounters set in and below a spooky crypt known as Shadowhaunt Mausoleum.
The DM should start by reading over the adventure to familiarize himself with the text. The sections titled Adventure Background, Adventure Setup, and Adventure Summary describe what's going on and what the characters are going to be doing. The section titled Potential Ally describes an interesting twist to the plot that allows wise characters to turn a deadly enemy into a helpful ally.