Adventure 3: Haunted Mansion

Adventure 3: Haunted Mansion is a text adventure game in which the player explores a haunted mansion and its immediate surroundings. Hidden in the game are 20 treasures for the player to find and return to their proper place. The game plays much like the previous games in the series and other treasure hunter text adventures from around the same time. The player can pick up and interact with items and must navigate from place to place. There is also a haunted forest where going back the way you came might not lead to the expected results.

The third and final game in O'Hare's Adventure series.

Unlike the other two games in the series, however, this game was not exclusive to the PET, as it got an official port to the Commodore 64 in 1983.