Mac is asked by Penny Parker to accompany her to a mansion she's apparently inherited from her Aunt Betty, who mysteriously died thirty years ago. Penny has the notion that the house is haunted, due to the talk that has been circulated about the house in the town. MacGyver has a tough time convincing Penny that "there are no such things as ghosts" as a result.
When they get into town, they meet a woman in a shop who knew Betty, and told Penny that she was crazy, not the good kind of crazy, mind you.
The first night they are there, a lightning storm hits the gazebo, knocking out the power. MacGyver rushes outside with Penny in pursuit to find out what exactly happened. When Penny finds a human skull, she becomes convinced that evil powers are at work in the house. Soon Penny starts to feel watched, and MacGyver's explanations for the sounds in the house seem feeble in contrast to the skull. Nonetheless, MacGyver, determined to solve the mystery of Aunt Betty's disapperance, creates a plaster model of what Betty would have looked like - exactly like Penny.
While upstairs, Penny starts hallucinating and a mysterious man comes from a panel in the wall and takes her downstairs. MacGyver rushes upstairs after hearing her scream. He finds the panel after some searching. Mac follows down the stairs and gets knocked out after finding Penny.
I won't reveal the ending, but I thought it was a decent episode of MacGyver. It certainly wasn't my favorite.