Follow Polterpup below the mansion
Polterpup steals the Front Entrance key. Follow the outside path to the well, restore its hanging handle and descend to the Bottom of the Well. Clear the Guard Tunnel encounter and continue to the Ceremonial Chamber. Carry fire to light the required torches. When possessed armor blocks you, lure it onto a rug and pull the rug from beneath its feet, then capture the exposed ghosts. Use the throne to enter the Haunted Catacombs. Dark-Light pawprints mark the story route through the maze.
Search the Underground Lab and Dungeon Cells
In the Underground Lab, vacuum the Greenies’ sunglasses before flashing them, then clear the Hider. Turn the back-wall wheel fully to reveal the Boo. The electrified armor drops a helmet; shoot it at the glass container for a diamond. The catacombs also hide a web-burning gem route marked by armor statues. Examine their swords for directions, restore the missing final statue, and use the web ball from the painting to burn the thick web. A nearby side door reaches the lower Cliffside diamond on a vine.
Return to Polterpup’s trail and enter the Dungeon Cells. Use Dark-Light on the bomb painting, carry the bomb through the broken bars and clear the obstruction. Repeat with the next cell’s painting as needed, then inspect the barrel at the end of the pawprints. Stun and vacuum the exposed dog to recover the front-door key.
Collectible checklist
Treacherous Mansion gems — #1 Underground Lab, #2 Haunted Catacombs, #3 Lower Cliffside
Boo checklist — Underground Lab: After clearing the ghosts, turn the rear wheel until its gauge reaches the end.