The Night of the Avaricious Actuary - S4.E11

Agents West and Gordon have been investigating a series of explosions that have demolished several palatial homes. While they are guests of the wealthy Mr. Taney, they hear a high, whining sound. Suddenly the house begins to crumble and the agents escape in the nick of time to see a giant tuning fork radiating powerful sound waves. As they delve deeper into the case, they discover a letter to Mr. Taney from the Cyclops Insurance Company, urging him to take out a policy against further destruction of his property.