"Blueprint for Murder" is the second story featured in Haunted Mansion #1. It was written and drawn by John "Bean" Hastings.
Narrated by Master Gracey, the story centers on the architects that built Gracey Manor: Mr. Coats and Mr. Davis. When their firm is contacted by Gracey to draw plans for his estate, he gives them specific demands for secret passages and unusual traps and - provided they remain discrete - offers them double the normal fare. Dividing the work, Coats and Davis each add their own designs to the mansion.
While on-site at the mansion's construction, Gracey sets a trap of his own: he pays a compliment to Mr. Davis in particular, mentioning that the "devil's in the details." Filled with jealousy and paranoid that Davis is trying to steal his limelight, Coats concocts a plan to do his partner in. Since the work is divided, its not difficult for Coats to slip some of his own secret designs into the construction drafts, and he schemes to be the sole wealthy architect if all goes well.
When the mansion is finished, Coats and Davis agree to be the first ones to visit it, and meet at midnight to explore the place. After being led through several of Davis's secret passages by his partner, Coats directs Davis to stand in a particular spot. He then pulls a wall sconce and causes a coffin to snap shut around Davis, sealing him inside. Coats gloats that his "Coats Automatic Hydraulic Coffinizer" has done its job, and that soon Davis will run out of air; since the coffin matches the rest of the eerie decor, Master Gracey won't find a coffin out-of-place enough to investigate.
However, Davis laughs in the coffin and says they had similar plans: he guided Coats exclusively through secret passages, which only he knew how to navigate. In a panic, Coats runs helplessly through the Endless Hallway, utterly lost, while Davis's laughter echoes through the corridors.
The story concludes with the reveal that Mr. Davis is now the Coffin Ghost that haunts the conservatory, while Coats is the invisible spirit that holds the floating candleabra in the Endless Hallway.
- Mr. Coats and Mr. Davis are obvious tributes to Imagineers Claude Coats and Marc Davis respectively. These two "architects" of the Haunted Mansion were noted for their differences of opinion during the ride's design, with Claude wanting more scares and Marc thinking the experience should be silly; the Coats and Davis of the story similarly differing in style, with Coats being more methodical and restrained and Davis being whimsical and quick.
- There are several nods to other Imagineers and talent involved in the creation of the attraction throughout the story, most notably as names on the spines of books in a background bookshelf.
- This story seems to contradict the mansion's history developed in the Mystery of the Manse storyline: in Haunted Mansion #3, William Gracey buys the house after abandoning his life as a pirate, and its already haunted, even noting that the original architects had disappeared shortly after house was complete; but "Blueprint for Murder" implies Gracey had the house built for him. It is possible that the house was built by a different Gracey, perhaps a relative of William, but this is merely speculation