Agatha Grisley was a mystery writer who had died before she could finish her latest manuscript.
Agatha Grisley was the greatest mystery writer and her stories were always the hardest to figure out, according to Winston at least. Grisley died during the composition of a new mystery novel, "Raoul's Revenge." She only made it to page 321 and never finished the story. A couple of weeks later, Grisley's will was being read at the Agatha Grisley Mansion. Grisley's ghost was not ready to move on until her book was completed. She used manifestations from her book to prompt the party present to finish.
The Ghostbusters were hired to capture Grisley. Winston Zeddemore happened to be a fan of the writer. Strange ghosts appeared throughout the mansion and acted out scenes from her novel. Upon discovering a trap door and Grisley's office, decorated with medieval torture sets, Zeddemore took the manuscript and vowed to finish it. The Ghostbusters realized that in order to get rid of the ghosts, they had to finish her novel and figure out the mystery. Zeddemore set the doctor as the culprit, who was upset his bill wasn't paid and his car insulted. Grisley was satisfied, took her lawyer's coat, and peacefully dispersed. The last page of the story included a dedication to Winston Zeddemore and the other Ghostbusters. Back at the Firehouse, Egon, Peter, and Ray watched a murder mystery and tried to figure out who did it. Winston was unable to join because he was bound and gagged, preventing him from giving away the culprit.
Agatha Grisley has the standard abilities of flight and intangibility. Her most unique ability is facilitating the manifestation of scenes from her unfinished novel. Upon scanning a manifestation involving a sword, the P.K.E. Meter got "strong readings." The readings were "hottest" on the second floor of the mansion.
- Agatha Grisley is a parody of the famous mystery novelist Agatha Christie.
- The knife in the front door reminded Winston of one of Grisley's previous works, "Murder on Hoboken Express." Chapter 12 to be precise.