"The Pickwick Capers" is the fourth story in Haunted Mansion #5. It is written and illustrated by Jon "Bean" Hastings.
The ghost of Erasmus Cromwell Pickwick narrates this story and explains the circumstances of how he came to join the happy haunts of Gracey Manor. Pickwick is a world-renowned thief, a self-categorized "mole burglar" due to his crippling acrophobia, acquired because his father built him an unsteady and lofty highchair as a baby. Using sewers and tunnels to his advantage, Pickwick stole many priceless items all throughout Europe, and eventually left to ply his illicit trade in the Americas.
While celebrating a recent successful heist in a pub one night, Pickwick's boasting that no place is safe from his burgling gets the attention of a strange old man, who claims Pickwick would never stand a chance trying to rob the nearby Gracey Manor. When asked what is worth stealing in a haunted mansion, the old man tells Pickwick of the fabulous pirate treasure Master Gracey supposedly hid there. Pickwick, who doesn't believe in ghosts, accepts the old man's challenge; and when the old man seemingly vanishes, the pub reacts with shock (though the old man pops up from behind his table a moment later, saying his fake accidentally popped out and fell on the floor).
Pickwick prepares for his heist by doing some research, and suspects the reputation of ghosts comes from the fact that Gracey's booby traps likely still function long after place was abandoned. He also learns of a secret passage through a mausoleum that leads him into the house: pushing the stone marked "M.T. Tomb" opens a hidden door leading underground.
Once Pickwick enters the mansion, he winds up in the Stretching Room, where his preparedness for the man-made does little to protect him from the supernatural. The room stretches, and the shock of seemingly sinking deeper and deeper eventually kills Pickwick, along with the sensation that there is no way out (no windows and no doors). Fortunately for Pickwick, his transition to a phantom has given him the power of levitation and cured his acrophobia, and now Pickwick hangs from the chandelier in the ballroom, having a grand time at the never-ending party.